CHEMISTRY LESSONS

PETROLEUM PROBLEMS

2009-05-18T23:53:00.000-07:00

1. Natural gas is a mixture of lightweight alkanes. A typical sample of natural gas when it is collected at its source contains methane, ethane, propane, butane and isobutane, and pentane. Some hydrocarbons are removed before the gas is sold. Which hydrocarbons are primarily contain in the commercial natural gas?
2. The propane and butane removed from natural gas are usually liquefied under pressure and sold. What is the name of this liquefied?
3. What are the use of both products above?
4. Crude oil is a complex mixture that is between 50 and 95% hydrocarbon by weight. What is the meaning of crude oil?
5. The first step in refining crude oil involves separating the oil into different hydrocarbon fractions by distillation. Which type of distillation is used in this process? Explain the meaning of it.
6. Make a table to show a typical set of petroleum fractions including the number of carbon atoms.
7. Petroleum is a mixture of hydrocarbon compounds. What are they?
8. Explain about fossil fuel, coal, natural gas, and bio gas.
9. Why petroleum couldn't be renewed?
10. What are the alternative fuels we can used?
11. Give the name of the following petroleum fractions and the use of each fraction.
a. C1 – C5
b. C5 – C10
c. C11 – C14
d. C13 – C17
e. C18 – C25
12. What are bitumen and naphtha? Explain the use of these.
13. Explain the difference of LNG and LPG.
14. What are the use of LNG and LPG?
15. What is the fractional petroleum which used as diesel machine?
16. What is the use of fractional petroleum which contains C atoms about 15 – 19?
17. What are the majority of hydrocarbon compounds in the pure gasoline?
18. Which substance contains in the gasoline that has a high value of combustion?
19. What is isooctane?
20. For a gasoline to function properly in an engine, it should not begin to burn before it is ignited by the spark plug. If it does, it gives engine “knock.” Explain the reason.
21. The anti-knock characteristics of a gasoline are rated by the octane-number scale. Explain about this.
22. Certain substances, such as tetraethyllead, were added to gasoline. What is the propose?
23. What does the octane rating for gasoline tell you?
24. There are a variety of gasoline. Explain please.
25. What are the difference among premix, pertamax, and pertamax plus?
26. What are the substances used for increasing the quality of gasoline?
27. What is TEL? Give the chemical formula and named it.
28. As anti-knocking, TEL is added into gasoline with another substance. What is it? Write the structural formula and named it.
29. Write the chemical equation when a certain gasoline that contain tetraethyllead and 1,2-dibromoethane is burnt.
30. The octane number of pure gasoline is 80%. What is the meaning of this percentage.
31. TEL can cause an air pollution. Explain the reason.
32. What is MTBE?
33. As an anti-knocking, MTBE is better than TEL. Explain the reason.
34. Recently, ethanol is also used as anti-knocking. Which one is better than the other, ethanol or MTBE? Give the reason.
35. Which anti-knocking can be used for pertamax plus?
36. A certain gasoline that contain anti-knocking has an octane number 92. What is the meaning of it?
37. Write the combustion reaction of gasoline.
38. Write the chemical equation when LNG and LPG are burnt in excess oxygen.
39. Propane has heat of combustion 2200 kJ/mol. Burning 22g propane should release … kJ.
40. Carbon dioxide is formed in the complete combustion of a fuel. Carbon monoxide can be formed in the incomplete combustion of a fuel. Write down the chemical equation.
41. If you are already using the proper octane fuel, what will happen?
42. Explain the following statement: a) The engine can be operating at optimum settings; b) A higher octane number should have no effect on the management system.
43. There is a reaction which used to break the long chain of hydrocarbon What is this reaction called?
44. What the different between refining and purifying?
45. Explain about cracking reaction.
46. Give an example of cracking process.
47. The cracking reaction is very important in the petroleum industry. What is the propose of doing this?
48. What are the products of cracking?
49. According to your opinion, is it useful or not? Give the reason.
50. Based on the economical argumentation, give your ideas please.
51. Cracking process can be used to provide gasoline with a high octane number. Give the reason.
52. What do you know about catalytic cracking? Explain please.
53. Cracking process needs a high temperature. Is it correct? Give the reason.
54. Hydrogen could well be a fuel for the future but there are advantages and disadvantages to its use. Explain please.
55. Please mention about greenhouse gases. Explain why those gases called as greenhouse gases.
56. What is the meaning of flammable or explosive?
57. What is the meaning of 'A substance releases energy on burning'? Are all fuels like this? Explain please.
58. What are the difference between combustion and burning?
59. Are all combustion reactions classified as an exothermic reaction?
60. Distinguish endothermic and exothermic processes.

HYDROCARBON REACTIONS PROBLEM

2009-05-04T00:08:00.000-07:00

1. Alkanes are non polar molecules. Explain the reason by giving an example.

2. Alkanes are called 'parafin.' What is the meaning of 'parafin?

3. Alkanes are saturated hydrocarbons and therefore, are generally less reactive than alkenes. Explain the reason.

4. Alkanes are unreactive towards polar or ionic reagents. Why?

5. Alkanes react with Br2 only in the presence of UV light. Give an example.

6. Which of the following statements is (are) correct regarding the reactivity of alkanes? Explain please.
a. Alkanes are generally inert.
b. Alkanes are polar molecules.
c. Alkanes are often used as solvents.
d. Alkanes react with acid.
e. Alkanes react with halogens.
f. Alkanes react with oxygen.

7. Explain that alkanes contain only strong sigma bonds.

8. The electronegativities of C and H are about the same, so C-H bonds have no significant polarity. Explain please.

9. All hydrocarbons burn easily in oxygens. What is the name of this reaction? Explain this type of reaction.

10. What the difference between complete combustion and incomplete one?

11. The large negative ∆H’s (exothermic reactions) explain why hydrocarbons are useful as fuels. Explain please.

12. When hydrocarbons burn in a limited supply of air (O2), what will happen?

13. Write down the balanced equation of complete combustion of ethane, propene, butyne.

14. Hydrocarbons only burn in the gaseous state. Explain the meaning of this statement.

15. What are the products of the combustion of 4-methyl-2-hexene in a limited oxygen?

16. The reaction of alkanes with halogens is called substitution. Explain by using an example.

17. What relative amounts of 1-bromo butane and 2-bromobutane are actually formed when butane is brominated?

18. What is the major product obtained from the monobromination of 2-methylbutane in the presence of light at room temperature?

19. What is the major product obtained from the monochlorination of 2-methylbutane in the presence of light at room temperature?

20. Alkanes react with the halogens via free-radical substitution reaction in the presence of sunlight. Explain this type of reaction.

21. When methane reacts with chlorine in sunlight, so what will happen?

22. What is the meaning of a chain reaction?

23. The mechanism of chain reaction of a substitution consists of four steps. What are they? Explain each of them by using an example.

24. Alkenes are more reactive than alkanes. Explain the reason.

25. An addition reaction is a reaction in which parts of a reactant are added to each carbon atom of a carbon–carbon double bond in alkenes. Give an example please.

26. Addition to triple bonds is also possible. Explain please.

27. What is the different between addition reaction in alkenes and alkynes?

28. What is the meaning of hydrogenation?

29. What is the product of the hydrogenation of 1-pentene and 2-pentene?

30. Write the equation of addition of Br2 to 1-butene; 2-butene; 2-methyl-1-butene; 2-methyl-2-butene.

31. There is (are) color change when the following substance(s) is (are) mixed with bromine water. Please choose and explain: ethene; n-butane; 2-butene; 2-methylpropane; 2-methylbutane; Cyclobutane.

32. The addition of Br2 to an alkene occurs so readily that bromine dissolved in carbon tetrachloride, CCl4. It is a useful reagent to test for unsaturation. Explain the reason.

33. What are the products of the addition of Br2 to cyclobutene and 3-methyl cyclopentene. Write down the equation and the name of the products.

34. Write down the equation of the addition of Cl2 to 2-methyl-2-pentene and 4-methyl-2-pentene.

35. Complete the following equation and give the name of the products.
a. C2H4 + Cl2 -->
b. C3H6 + Br2 -->

36. If an excess of Br2 is added to CH ≡ CH, what is the correct product. Write down the rquation.

37. What the reactant used to produce the following prodcts? Write down the equation.
a. CH3CBr=CHBr
b. CHBr2-CHBr2
c. CHBr=CBrCH2CH3

38. What is the difference between substitution reaction and addition?

39. Explain the statement of Markownikoff’s rule

40. What is the main product when HBr adds to 1-pentene? Write the equation.

41. Write the equation of addition of HCl to 2-methyl-2-pentene.

42. If an excess of HCl is added to CH3CH2C≡CH, what is the product? Write the equation.

43. What is the product of addition of excess bromine to 2-propyne? Write the equation.

44. When calcium carbide is added to water, a flammable gas is formed. Write the equation.

45. Acetylene is called carbide gas. Explain the reason.

46. Write the equation of the reaction between CH2CHCH2CH3 and H2O(g).

47. When ethene is added to alkaline KMnO4 at room temperature, it is oxidized. Write the equation.

48. If an excess of MnO4- in an acid solution is added to CH2CH2, what is the product? Write the equation.

49. Ethene undergoes addition polymerization. Write the equation.

50. What is the major result of the elimination reaction of ethanol? Write the equation.

51. If 1-pronanol is added by sulfuric acid at 180ºC, the main product is ….a. Propaneb. propunec. propened. 2-propanole. Propilsulphate

52. When 1-butanol is added by sulfuric acid at 180ºC , what is the major product? Write the equation.

53. Propylchloride reacts with potassium hydroxide in alcohol. What is the major product? Write the equation.

54. Butylbromide reacts with potassium hydroxide in alcohol. Write the equation.

55. What reagents would you need to change hexylchloride become 1-hexene?

56. Write the above equation.

57. What reagents would you need to prepare 3-bromo-2-pentanol?

58. Write the above equation.

59. Which reactant could be dehydrohalogenated to give 2-butyne?

60. Write the above equation.

PETROLEUM QUIZ

2009-04-29T09:55:00.000-07:00

1. Petroleum is a mixture of … with smaller amounts of aromatic hydrocarbons.

a. alkanes and alkenes

b. alkanes and cycloalkanes

c. alkenes and cycloalkanes

d. alkynes and alkenes

e. alkynes and alkanes

2. Petroleum can be classified as mixture of ….

a. hydrocarbon

b. aliphatic hydrocarbon

c. aromatic hydrocarbon

d. aliphatic and alisiclic hydrocarbon

e. aliphatic ans aromatic hydrocarbon

3. The method used to separate the components of petroleum is named ….

a. destilation

b. fractional destilation

c. heating

d. fractional heating

e. filtration

4. The wrong information about fossil fuels is ….

a. the principal sources of hydrocarbons

b. can form as natural gas, petroleum, and coal

c. it is separated by distillation into fractions such as biogas V

d. natural gas is mainly methane with smaller amounts of the other gaseous alkanes

e. petroleum is a mixture of alkanes and cycloalkanes with smaller amounts of aromatic hydrocarbons

5. Natural gas and petroleum, which are mixtures of hydrocarbons, are the major sources of organic chemicals. By various reactions, the hydrocarbons in natural gas and petroleum are converted to final products, such as ….

a. fibers

b. solvents

c. plastics

d. cartoon

e. textile

6. Crude oil is separated into different fractions with different boiling points and composition by fractional distillation. The wrong answer about these fractions is ….

a. Gas C1 – C5 gas cookers

b. Gasoline C5 – C10 combustion engines

c. Kerosene C11 – C14 roofing

d. light gas-oil C13 – C17 diesel engines

e. heavy gas-oil C18 – C25 lubricants

7. Petroleum can be separated into petroleum fraction by fractional distillation because the fraction …..

a. are miscible

b. have different viscosities

c. have different boiling point

d. have similar chemical properties

e. have different freezing point

8. Fraction distillation of a sample of cruide oil produce the fraction . The boiling point of the fraction are given below. Which fraction has the biggest molecules?

Fraction Approximate boling points (oC)

A 20 - 40

B 40 – 120

C 120 – 160

D 160 – 250

E Above 250

9. Which one of the following hydrocarbons would you expect to find in petroleum gas ?

a. C3H8

b. C16H34

c. C6H14

d. C17H36

e. C7H16

10. One of the following compounds that might be found in kerosene is ….

a. n- nonane

b. n-dekane

c. 2-methyloctane

d. 3-ethyldekane

e. 2,3-dimethylheptane

11. Fractional distillation can be used to separate crude into kerosene, diesel oil, lubricating oil and petrol. What is the correct order of their boiling points ?.

Lowest boiling point  Highest boiling point

A Lubri-cating oil Kero-sene Diesel Lubri-cating oil

B Kero-sene Diesel Lubri-cating oil Petrol

C Diesel Kero-sene Lubri-cating oil Petrol

D Lubri-cating oil Kero-sene Petrol Petrol

E Kero-sene Diesel Petrol Lubri-cating oil

12. Which of the following petroleum fraction is correctly matched to its use ?

a. Bitumen, as feedstock for chemical industry

b. Naptha, for making road

c. Lubricating oil, for making polishes and waxes

d. Diesel oil, as jet fuel

e. LNG, for making plastic

13. Which substance is found in petrol?

a. C

b. CO

c. CO2

d. H2

e. C8H18

14. At which location in this distillation column will petroleum gas, C1 - C4 hydrocarbons, be most likely to be collected?

a. A

b. B

c. C

d. D

15. Natural gas is mainly … with smaller amounts of the other gaseous alkanes.

a. methane

b. ethane

c. propane

d. butane

e. pentane

16. The wrong statement about LNG is ….

a. liquefied petroleum gas

b. natural gas in its liquid form.

c. when it is cooled to minus -161ºC, it becomes colorless and odorless

d. neither corrosive nor toxic.

e. primarily methane

17. The hydrocarbons found in LPG contain … carbon atoms per molecule.

a. 1-2

b. 3-4

c. 5-12

d. 13-18

e. 17

18. LPG is ….

a. Liquified Gas of Gasoline

b. Motor cycle’s fuel

c. methane

d. ethane

e. gas fuel

19. Gasoline hydrocarbons contain … carbon atoms per molecule.

a. 1-2

b. 3-4

c. 5-12

d. 13-18

e. 17

20. The fractional petroleum which contains C atoms about 15 - 19 is used as ....

a. fuel for car

b. fuel for motor cycle

c. pump

d. diesel machine

e. lubricants

21. The substance contains in the gasoline that has a high value of combustion is ....

a. heptane

b. isoheptane

c. isooctane

d. octane

e. 2-methylheptane

22. The systematical name of isooctane is ....

a. 2-methylheptane

b. 2-methyloctane

c. 2,4-dimethylhexane

d. 2,2,4-trimethylpentane

e. 2,2,4-trimethyloctane

23. The formulae of isooctane is ....

a. (CH3)2(CH2)6

b. (CH3)2CH(CH2)5

c. (CH3)3CCH2CH(CH3)2

d. (CH3)3C(CH2)3CH3

e. (CH3)3CCH2CH(CH3)2

24. For a gasoline to function properly in an engine, it should not begin to burn before it is ignited by the spark plug. If it does, it gives engine “knock.” The antiknock characteristics of a gasoline are rated by the octane-number scale. This scale is based on ….

a. heptane, given an octane number of 0

b. heptane, given an octane number of 100

c. 2,2,4-trimethylpentane, given an octane number of 0

d. 2,2,4-trimethylpentane, given an octane number of 100

e. heptane with the octane no. of 0 and isooctane with the octane no. of 100 V

25. Certain substances, such as tetraethyllead, Pb(C2H5)4 were added to gasoline to ….

a. raise the octane number

b. raise the amounts of isooctane

c. decrease the amounts of antiknock

d. decrease the octane rating

e. increase the amounts of n-heptane

26. What does the octane rating for gasoline tell you?

a. amino acids

b. carboxylic acids

c. the tendency of fuel to knock.

d. the number of carbon atoms

e. the rate of combustion

27. The substance used for increasing the quality of gasoline is ….

a. TEL

b. alcohol

c. acetone

d. formaline

e. lead

28. TEL is ….

a. tertier lead

b. tertier ethyl lead

c. tetraethylene

d. tetraethyl lead

e. tetratoluene

29. The formulae of TEL is ….

a. Pb(C2H5)4

b. Pb(CH3)4

c. C2H5Pb

d. C2H5OH

e. CH3OH

30. As anti-knocking, TEL is added into gasoline with another substance. This is ….

a. bromo ethane

b. 1,2-dibromo ethane

c. ethane

d. chloro ethane

e. 1,2-dichloro ethane

31. The formulae of 1,2-dibromoethane is ....

a. CH3CHBr2

b. CHBr2CH3

c. CH2BrCH2Br

d. CH2BrCH3

e. CH3CH2Br

32. When a certain gasoline that contain tetraethyllead and 1,2-dibromoethane is burnt, it will produce ....

a. CO2, H2O

b. CO2, H2O, Br2

c. CO2, H2O, Pb

d. CO2, H2O, PbBr2

e. CO2, H2O, PbO, Br2

33. The octane number of pure gasoline is 80%. The meaning of this percentage is the fuel contains ....

a. octane : heptane = 4 : 2

b. 80% octane and 20% heptane

c. 80 % heptane and 20% octane

d. 100% long chain hydrocarbon

e. 80% octane

34. The following substances might be used as anti-knocking.

1. ethanol

2. Pb(C2H5)4

3. MTBE

The anti-knocking which used in the pertamax plus is ….

a. 1

b. 2

c. 3

d. 1 and 2

e. 1 and 3

35. The gasoline which has the octane number more than 92 is (are) ….

1. premix

2. pertamax

3. pertamax plus

a. 1

b. 2

c. 3

d. 1 and 2

e. 2 and 3

36. Recently, tetraethyllead doesn’t use for anti-knocking, because it ….

a. contains Pb

b. caused air pollution

c. doesn’t work properly

d. reacts with gasoline

e. consists of molecules

37. MTBE is ….

a. methyl tersierbutyl ether

b. methane tribromo ether

c. methyl tribromo ether

d. methyl tributyl ethane

e. methyl tersierbutyl ethane

38. The formulae of MTBE is ….

a. CH3O(CH2)3

b. CH3OC(CH3)3

c. CH3OCH(CH3)3

d. CH3OCH2C(CH3)2

e. CH3O(CH3)3

39. The products when natural gas or petroleum are burnt in excess oxygen is ….

a. C

b. CO

c. CO2

d. C and CO

e. C and CO2

40. Propane has heat of combustion 2200 kJ/mol. Burning 22g propane should release … kJ.

a. 550

b. 1100

c. 2200

d. 3300

e. 4400

41. Carbon dioxide is formed in the complete combustion of a fuel. Carbon monoxide can be formed in the incomplete combustion of a fuel. Which statement is TRUE about these two gases?

a. neither compound will burn in air

b. both gases are compounds

c. both gases are toxic to animals

d. both gases give a milky precipitate when bubbled into limewater

42. There are many aspects to consider regarding gasoline as a consumer item. Which is false?

a. Gasoline is a mixture of molecules, containing mostly hydrocarbons.

b. Several decades ago, tetraethyl lead was used as a gasoline additive to control engine "knocking."

c. Oxygenated additives like ethanol help lower emissions and raise the octane rating.

d. None of the answers are false; all are true.

43. Petroleum is separated by distillation into fractions such as gasoline and kerosene. These fractions are usually processed further—for example, to obtain a greater quantity of gasoline with the desired fuel characteristics. This processing is called ….

a. refining

b. solubility

c. filtration

d. evaporation

e. coagulation

44. If you are already using the proper octane fuel, you will:

1. not obtain more power from higher octane fuels.

2. The engine will be already operating at optimum settings

3. a higher octane should have no effect on the management system.

The correct answer is (are) ….

a. 1 only

b. 2 only

c. 3 only

d. 1 and 2 only

e. 1, 2, and 3

45. The reaction which used to break the long chain of hydrocarbon is called ....

a. cracking

b. refining

c. purifying

d. anodizing

e. oxidazing

46. One of the equations below is the cracking reaction. The correct answer is ….

a. C17H36C8H18+CH3CH=CH2+3CH2=CH2

b. C17H36 + 26 O2  17 CO2 + 18 H2O

c. C8H16 + H2  C8H18

d. C8H16 + Br2  C8H16Br2

e. C8H16 + HCl  C8H17Cl

47. The cracking reaction is very important in the petroleum industry. The wrong information below is ….

a. as a source of alkenes

b. it is used to provide extra kerosene

c. provide gasoline of a high octane rating

d. under the right conditions usually produce ethene and propene

e. tends to produce branched-chain rather than straight-chain alkanes

48. Cracking process can be used to provide gasoline with a high octane number, because it can produce ….

a. gasoline

b. certain alkane

c. isooctane

d. n-heptane

e. isooctane and n-heptane

49. The statements below are about a catalytic cracking. The wrong statement is ….

a. Al2O3/SiO2 are as catalysts

b. can undergo at lower temperature

c. hydrogen gas may also be produced

d. alkane with larger molecules cannot be cracked

e. alkane with smaller molecules will be produced

50. Catalytic cracking of C16H34 will produce ….

a. octene and octane

b. octane only

c. octene only

d. benzene and decane

e. hexane and decane

51. Cracking process needs a high temperature, because ....

a. it needs energy

b. the reaction is exotherm

c. the reaction is endotherm

d. the reactant is a polar substance

e. the reactant is a non polar substance

52. Hydrogen could well be a fuel for the future but there are advantages and disadvantages to its use. Which statement is TRUE about the potential use of hydrogen as a fuel?

a. on burning it produces lots of greenhouse gases

b. on burning it gives off lots of wasted light energy

c. it has to be compressed before it can be distributed efficiently

d. it is not as flammable or explosive as

53. Which word would you associate with the phrase 'a substance that releases energy on burning'?

a. Endothermic

b. Exothermic

c. Reactive

d. Fuel

e. Combustion

54. Which of these is a desirable property of a fuel for burning?

a. difficult to ignite so not too flammable

b. gives bright clear flame

c. will not burn too steadily to be wasteful

d. gives moderate amount of smoke

HYDROCARBON REACTIONS QUIZ

2009-04-29T09:53:00.000-07:00

1. Alkanes are saturated hydrocarbons and therefore, are generally ….
a. reactive
b. unreactive
c. quite reactive
d. more reactive than alkenes
e. less reactive than alkenes

2. Alkanes are saturated hydrocarbons. The following statements are correct about alkanes, except ….
a. generally reactive
b. the molecules are non-polar
c. the general formulae is CnH2n+2
d. unreactive towards polar or ionic reagents
e. react with Br2 only in the presence of UV light

3. Alkanes are non-polar and so, are unreactive towards ….
a. non-polar reagens
b. ionic reagents
c. oxygen
d. halogens
e. hydrogen halides

4. Which of the following statements is NOT correct regarding the reactivity of alkanes?
a. Alkanes are generally inert.
b. Alkanes react with acids and bases.
c. Alkanes are often used as solvents for chemical reactions.
d. Alkanes react with halogens and oxygen upon ignition.

5. Which of the following statements about alkanes is not correct?
a. Alkanes contain only strong sigma bonds.
b. Alkanes do not contain any double or triple bonds.
c. The electronegativities of C and H are about the same, so C-H bonds have no significant polarity.
d. The electronegativities of C and H differ greatly; the H is the negative pole of the bond.

6. All hydrocarbons burn easily in an excess oxygens to form carbon dioxide and water. This reaction is classified as ….
a. redox
b. reduction
c. incomplete burning
d. complete combustion
e. incomplete combustion

7. All hydrocarbons burn easily in an excess of O2 to give carbon dioxide and water. The large negative ∆H’s (exothermic reactions) explain why hydrocarbons are useful as fuels. When hydrocarbons burn in a limited supply of air (O2), the products is (are) ….
a. carbon dioxide
b. carbon monoxide and carbon
c. carbon monoxide, carbon, and water
d. carbon dioxide and carbon monoxide
e. carbon dioxide, carbon monoxide, carbon and water V

8. The large negative ∆H’s explain why hydro-carbons are useful as fuels. The following properties that unrelated to the above information is ….
a. endothermic
b. release energy
c. can produce fire
d. react with oxygen
e. easily to be burned

9. The correct chemical equation of complete combustion in general is ….
a. CxHy + O2  CO + H2O
b. CxHy + O2  CO2 + H2O
c. CxHy + O2  x CO2 + y/2 H2O
d. CxHy + (x+y) O2  x CO + y H2O
e. CxHy + (x+y/4) O2  x CO2 + y/2 H2O

10. Hydrocarbons only burn in the gaseous state. The meaning of this statement is ….
a. solid hydrocarbons can not be burned
b. liquid hydrocarbons are difficult to be burned
c. in the gaseous state, the number of molecules decrease
d. each molecule of hydrocarbons gas is far one of another
e. the molecule is easily reacting, because its mass decreases

11. The following statements which correct about burning hydrocarbons is ….
a. less volatile hydrocarbons burn less readily
b. solid hydrocarbons must be vaporized before burning
c. CO and C are also formed in an incomplete combustion
d. for completing combustion, an excess oxygen is needed
e. when hydrocarbons burn in a limited oxygen, still produce CO2

12. The products of the balanced equation for the combustion of propane are ….
a. 2CO2 + 4H2O
b. 3CO + 4H2O
c. 3CO2 + 4H2O
d. 4H2O
e. 8H2O

13. Balance the following combustion reaction of hexane by supplying the correct coefficient in front of the other three species.
C6H14 + __O2  __CO2 + __H2O
What is the coefficient in front of O2?
a. 5/2
b. 13/2
c. 19/2
d. 8
e. 10

14. The balanced equation for the combustion of pentane is ….
a. C3H8 + 5 O2 → 3 CO2 + 4 H2O
b. C5H12 + 8 O2 → 5 CO2 + 6 H2O
c. 2 C3H8 + O2 → 3 CH4 + 2 H2O
d. 2 C5H12 + 2 O2 → 10 CH4 + 2 H2O
e. 4 C5H12 + 2 O2 → 20 CH4 + 4 H2O

15. What are the products of the combustion of 4-methyl-2-hexene?
a. Smaller hydrocarbons
b. CH4 and H2O
c. CO2 and H2O
d. C and H2O

16. The reaction of alkanes with halogens is called ….
a. addition
b. substitution
c. oxidation
d. combustion
e. hydrogenation

17. A substitution reaction is a reaction in which a part of the reagent molecule is substituted for … on a hydrocarbon or hydrocarbon group.
a. H atom
b. O atom
c. Cl atom
d. H2 molecule
e. Cl2 molecule

18. All of the H atoms of an alkane may undergo substitution, leading to a mixture of products. The correct answer is ….
a. bromine is the most reactive reagent
b. chlorine is more reactive than fluorine
c. bromine is more reactive than chlorine
d. fluorine is very reactive, usually gives complete substitution
e. chlorine is less reactive than bromine, often requires elevated temperatures

19. What relative amounts of 1-bromo butane and 2-bromobutane are actually formed when butane is brominated?
a. 1-bromobutane : 2-bromobutane = 1 : 55
b. 1-bromobutane : 2-bromobutane = 55 : 1
c. 1-bromobutane : 2-bromobutane = 1 : 25
d. 1-bromobutane : 2-bromobutane = 25 : 1
e. 1-bromobutane : 2-bromobutane = 3 : 2

20. What is the major product obtained from the monobromination of 2-methylbutane in the presence of light at room temperature?
a. 1-bromo-2-methylbutane
b. 2-bromo-2-methylbutane
c. 2-bromo-3-methylbutane
d. 3-bromo-2-methylbutane
e. 1-bromo-3-methylbutane

21. What is the major product obtained from the monochlorination of 2-methylbutane in the presence of light at room temperature?
a. 1-chloro-2-methylbutane
b. 2-chloro-2-methylbutane
c. 2-chloro-3-methylbutane
d. 3-chloro-2-methylbutane
e. 1-bromo-3-methylpentane

22. Alkanes react with the halogens via free-radical substitution reaction in the presence of sunlight. When methane reacts with chlorine in sunlight, so ….
a. a chain reaction is may not be occurred
b. a carbon tetrachloride is the main product
c. one or more chlorine atoms may replease hydrogen atoms
d. the products do not depend on the amounts of halogen and alkane
e. the yellowish-green colour of Cl2 fades and HCl(g) can be detected

23. The wrong information about a chain reaction of a substitution is ….
a. the mechanism consists of four steps
b. the slow step reaction is the formation of free radical
c. the reaction does not proceed in the dark at room temperature
d. in the propagation, the free radicals attact the alkane molecules
e. the chain reaction is terminated when two free radicals combine

24. From the following mechanism, the termination equation is ….
a. Cl2  Cl* + Cl*
b. Cl* + CH4  CH3* + HCl
c. CH3* + Cl2  CH3Cl + Cl*
d. CH3* + CH2Cl*  CH3CH2Cl
e. Cl* + CH3Cl  CH2Cl* + HCl

25. Alkenes are more reactive than alkanes because of the presence of ….
a. the single bond
b. the double bond
c. the triple bond
d. the carbon atoms
e. the hydrogen atoms

26. An addition reaction is a reaction in which parts of a reactant are added to each carbon atom of a carbon–carbon double bond, which then ….
a. has enough carbon atoms
b. the length of the chain increases
c. the atoms of hydrogen increase
d. becomes a carbon–carbon single bond
e. the number of carbon-carbon double bond decrease

27. Addition to triple bonds is also possible, giving a product with ….
a. a single bond
b. a single bond and a double bond
c. a single bond, if there is an excess reactant
d. a double bond, if there is an excess reactant
e. a triple bond, if there is not enough reactant

28. The product of the hydrogenation of 2-butene is ….
a. n-butane
b. butane
c. 2-butane
d. 2-butene
e. 2-methylpropane

29. The addition of Br2 to an alkene is ….
a. very slow
b. very fast
c. faster than Cl2
d. slower than Cl2
e. quite slow

30. With which of the following would you expect to observe a color change when it was mixed with bromine water?
a. n-butane
b. 2-butene
c. 2-methylpropane
d. 2-methylbutane
e. Cyclobutane

31. The addition of Br2 to an alkene occurs so readily that bromine dissolved in carbon tetrachloride, CCl4. It is a useful reagent to test for unsaturation. When a few drops of the solution are added to an alkene, so ….
a. the bromine immediately react
b. the color of bromine changes
c. the reaction occurs suddently
d. the redbrown color of the bromine changes
e. the redbrown color of the bromine is immediately lost

32. The addition of Br2 to cyclohexene gives ….
a. o-bromocyclohexane
b. bromocyclohexane
c. 1-bromocyclohexane
d. 1-bromocyclohexene
e. 1,2-dibromocyclohexane

33. The addition of hydrogen to 3-methyl cyclopentene gives the product named ….
a. 2-methylcyclopentane
b. 3-methylcyclopentane
c. methylcyclopentane
d. cyclopentene
e. cyclopentane

34. The addition of Cl2 to 4-methyl-2-pentene gives the product named ….
a. 2,3-dichloro-2-methylpentane
b. 3, 4-dichloro-2-methylpentane
c. 3, 4-dichloro-2-methylpentene
d. 2, 3- dichloro-4-methylpentane
e. 2, 3- dichloro-4-methylpentene

35. Complete the following equation:
C3H6 + Br2 
The product is ....
a. C3H6Br2
b. C3H5Br
c. C3H5Br + HBr
d. CH3Br + C2H3Br
e. no reaction

36. If an excess of Br2 is added to CH ≡ CH, the correct product is ….
a. CHBr=CHBr
b. CHBr2-CHBr2
c. CH2=CBr2
d. dibromoethene
e. tetrabromoethene

37. The following statements are correct about an addition reaction, except ….
a. HCl and HBr are unsymmetrical reagents
b. 1-butene is an unsymmetrical alkene
c. two products that are isomers will occurred in equal amounts v
d. the H atom of HBr adds to C atom 1, giving 2-bromopropane
e. the H atom of HBr adds to C atom 2, giving 1-bromopropane

38. The correct statement about the Markownikoff’s rule is ….
a. the richer gets rich
b. there is only one product formed
c. HBr is a symmetrical reagents
d. H2O could not be added to alkenes
e. H atom of HCl attacts C atom of C = C

39. The main product when HBr adds to 1-butene is ….
a. 2-butene
b. n-butane
c. 1-bromobutene
d. 1-bromobutane
e. 2-bromobutane

40. The addition of HCl to 2-methyl-2-butene follows Markovnikov's Rule. The product is ….
a. 2,3-dichloro-2-methylbutane
b. 2-chloro-2-methylbutane
c. 3-chloro-2-methylbutane
d. 1-chloro-2-methylbutane
e. 2-chlorobutane

41. The alkynes also undergo addition reactions, usually adding … molecule(s) of the reagent for each C ≡ C bond.
a. 1
b. 2
c. 3
d. 4
e. 5

42. If an excess of HCl is added to CH3C≡CH, the product is ….
a. propene
b. propane
c. 1-chloropropene
d. 1,1-dichloropropane
e. 2,2-dichloropropane

43. The product of addition of excess bromine to 2-butyne is ….
a. 2,2,3,3-tetrabromobutane
b. 2,2-dibromobutane
c. 1,4-dibromobutane
d. 1,2,3,4-tetrabromobutane

44. When calcium carbide is added to water, a flammable gas is formed. The gas is
a. carbon dioxide
b. methane
c. ethane
d. acetylene

45. The reaction between CH2CHCH3 and H2O(g) will produce ….
a. Propene
b. propane
c. 1-propanol
d. 2-propanol
e. 1,2-propanediol

46. When ethene is added to alkaline KMnO4 at room temperature, it is oxidized to give ….
a. ethanol
b. ethenediol
c. 1,1-ethanediol
d. 1,2-ethanediol
e. 2,2-ethanediol

47. If an excess of MnO4- in an acid solution is added to CH2CH2, the product is ….
a. methanal
b. ethanal
c. C and H2O
d. CO and H2O
e. CO2 and H2O

48. Ethene undergoes addition polymerization to give ….
a. ethane
b. butane
c. micromolecules
d. polyethene
e. polyethane

49. The major result of the elimination reaction of ethanol is ….
a. ethane
b. ethene
c. ethyloxide
d. ethylchloride
e. ethylhydroxide

50. If 1-pronanol is added by sulfuric acid at 180ºC, the main product is ….
a. Propane
b. propune
c. propene
d. 2-propanol
e. Propilsulphate

51. When 1-butanol is added by sulfuric acid at 180ºC , the major product is ….
a. butane
b. 1-butyne
c. 1-butene
d. 2-butanol
e. butylsulphate

52. Propylchloride reacts with potassium hydroxide in alcohol. The major product is ….
a. 1-chloropronane
b. 2-chloropropane
c. 1-chloropropene
d. propane
e. propene

53. Butylbromide reacts with potassium hydroxide in alcohol. The main product is ….
a. 1-chlorobutane
b. 2-chlorobutane
c. 1-chlorobutane
d. butane
e. butene

54. What reagents would you need to change butilchloride become 1-butene?
a. KOH
b. NaOH
c. KOH + C2H5OH
d. H2O
e. HCl

55. What reagents would you need to prepare 3-bromo-2-butanol?
a. 2-butene and HBr
b. 1-butene, Br2, and water
c. 1-butene, HBr, and water
d. 2-butene, HBr, and water
e. 2-butene, Br2, and water

56. Which of the following could be dehydrohalogenated to give 2-butyne?
a. 2,2,3,3-tetrabromobutane
b. 2,2-dibromobutane
c. 1,4-dibromobutane
d. 1,2,3,4-tetrabromobutane

HYDROCARBON ISOMER QUIZ

2009-04-29T09:49:00.000-07:00

1. Structural isomers have the same molecular formula but different ….
a. molecular mass
b. structural formula.
c. number of atoms
d. empirical formula
e. atomic structures

2. n-butane and isobutane have different ….
(1) structural formulae
(2) physical properties
(3) chemical properties
(4) molecular formulase

a. (1), (2), (3)
b. (1), (3)
c. (2), (4)
d. (4)
e. (1), (2), (3), (4)

3. Butane and isobutane are structural isomers, compounds with the same molecular formula but different structural formulas. Because these isomers have different structures, they have different ….
a. mass
b. volume
c. boiling point
d. molecular mass relative
e. mass’ percentage of elements

4. How many different structural isomers are there for a hydrocarbon with the formula C6H14?
a. 1
b. 2
c. 3
d. 4
e. 5

5. Which possible formula is an isomer of pentane?
a. 1-methylbutane
b. 2-methylbutane
c. 1,2-dimethylbutane
d. 2,2-dimethylbutane
e. 3-methylbutane

6. The names of two structural isomers of C6H14 are ….
a. 2-methylpentane and 2,2-dimethylbutane
b. hexane and 2-methylpentane
c. 2,2-dimethylbutane and hexane
d. 2-methylbutane and 2,2-dimethylpropane
e. 2,3-dimethylbutane and 1,3-dimethylbutane

7. The following pairs which isomers are ..
a. n-heptane and cycloheptane
b. 2-methylpentane and n-pentane
c. 3-ethylpentane and 3-ethylheptane
d. 3-ethylpentane and 2-methyl heptane
e. 3-methylpentane and3-methylbutane

8. Which of the following pairs represent structural isomers?
a. propane and butane
b. 2-methylbutane and butane
c. 2-methylpropane and propane
d. 2-methylpentane and 2,3-dimethylbutane
e. 2,2-dimethylpentane and 2,2-dimethylbutane

9. Hexane, C6H14, has how many structural isomers, and how many of these are branched hydrocarbons?
a. 3 structural isomers, 1 branched
b. 4 structural isomers, 2 branched
c. 4 structural isomers, 3 branched
d. 5 structural isomers, 3 branched
e. 5 structural isomers, 4 branched

10. Which pair of compounds are C5H12?
a. n-pentane and 1-methylbutane
b. 1-methylbutane and 2-methylbutane
c. 2-methylbutane and 3-methylbutane
d. 2-methylbutane and 2,2-dimethylpropane
e. 1,2-dimethylpropane and 2,2-dimethylpropane

11. How many structural isomers does pentane have?
a. 2
b. 3
c. 4
d. 5
e. 6

12. Including pentane itself, how many chain isomers can pentane be drawn as?
a. 2
b. 3
c. 4
d. 5
e. 6

13. The isomer of pentane is ….
a. C(CH3)4
b. CH3 – (CH2)2 – CH3
c. CH(CH3)2 – CH2 – CH2 – CH3
d. CH3 – CH2 – (CH3) – CH3
e. CH3 – (CH2)3 – CH(CH3)2

14. The following compounds are isomers of hexane, except ….
a. 3-methyl pentane
b. 2,2 – dimethyl propane
c. 2,3 – dimethyl butane
d. 2-methylpentane
e. 2,2 – dimethyl butane

15. The special type of isomers for alkane group is ….
a. chain isomers
b. geometric isomers
c. positional isomers
d. functional isomers
e. structural isomers

16. 2-methyl-1-propene is chain isomer of ….
a. 1-propene
b. 1-butene
c. 2-butene
d. 2-methyl-1-butene
e. 2-methyl-1-pentene

17. Which compounds are classified as chain isomers?
a. ethene and propene
b. 2-butene and 2-pentene
c. propene and 2-methyl-1-propene
d. 2 metil-1-propena and 2 metil-1-butena
e. 5-ethyl-2-methyl-3-heptene and 2,2,5,5-tetra methyl-3-heksene

18. Positional isomer of 1-hexene is ….
a. 2-hexene
b. 1,2-hexadiene
c. 2-methylpentene
d. 3-methylpentene
e. 2,3-dimethylbutene

19. 1-pentene and 2-pentene can be classified as ….
a. chain isomers
b. geometric isomers
c. positional isomers
d. functional isomers
e. structural isomers

20. How many isomers are there of C5H11Cl?
a. Five
b. Six
c. Seven
d. Eight
e. Nine

21. 1-chlorobutane and 2-chlorobutane are ….
a. chain isomers
b. geometric isomers
c. positional isomers
d. functional isomers
e. structural isomers

22. Both chain and positional isomers can be shown by …
a. 1-propene and 1-butene
b. 1-butene and 2-butene
c. 1-butene and 2-methyl-1-propene
d. 1-pentene and 2-methyl-1-butene
e. 1-pentene and 2-methyl-2-butene

23. Cyclobutane (a four carbon ring with all carbon-carbon single bonds and having the molecular formula C4H8 is an isomer of ….
a. butyne
b. butane
c. 1-butene
d. 2-methylpropane
e. butadiene

24. Cyclobutane and 2-butene can be classified as … isomers.
a. chain
b. position
c. function
d. geometric
e. optic

25. Functional isomers can be found in the following compounds. The correct answer is ….
(1) alkene
(2) alkyne
(3) cycloalkane
(4) alkadiene

a. (1) and (2)
b. (1) and (3)
c. (2) and (3)
d. (1) and (4)
e. (3) and (4)

26. 1,3-butadiene is functional isomer with ….
a. 1-butyne
b. 1,3-dibutyne
c. 2-methylpropene
d. 1-butene
e. 2-butene

27. CH3CH=CHCH2CH=CHCH3 is functional isomer with ….
a. 2,5-heptadiene
b. 1,2-heptadiene
c. 5-methyl-1,2-hexadiene
d. 1-methyl-cyclohexane
e. 2-heptyne

28. Which of the following could represent a compound that exhibits geometrical isomerism?
a. C3H6
b. C3H8
c. C4H8
d. C4H10
e. Benzene

29. What feature of the C=C bond in alkenes causes cis/trans isomerism?
a. Its weight
b. Its length
c. Its strength
d. The fact it cannot be broken
e. The fact it is difficult to rotate the bond

30. The following compounds have geometrical isomers, except ….
a. 2-butene
b. 2-methyl-2-butene
c. 2-hexene
d. 3-hexene
e. 2-methyl-3-hexene

31. The name of the isomer of 2-butene with the methyl groups on opposite sides of the double bond is ….
a. 2-butene
b. cis-2-butene
c. trans-2-butene
d. dimethylethylene
e. 2,2-dimethylethylene

32. Which of the following alkenes can have cis-trans isomers?
1. 1-butene
2. 2-butene
3. 2-methyl-1-propene

a. 1 only
b. 2 only
c. 3 only
d. 1 and 2
e. 1, 2, and 3

33. The possible isomers of 2,3-dichloro-2-butene are ….
(1) 1,2-dichloro-2-butene
(2) 2,3-dichloro-1-butene
(3) Cis-1,2-dichloro-2-butene
(4) Trans-1,2-dichloro-2-butene

a. (1), (2), (3)
b. (1), (3)
c. (2), (4)
d. (4)
e. (1), (2), (3), (4)

34. What is the best name for the molecule below?

a. cis-4-methyl-2-hexene
b. trans-4-methyl-2-hexene
c. cis-4-ethyl-2-pentene
d. trans-2-ethyl-3-pentene
e. cis-2-ethyl-3-pentene

35. The above line formula has ….

a. 9 carbon atoms, one double covalent bond, 5 single covalent bonds, 14 hydrogen atoms
b. 7 carbon atoms, one double covalent bond, 5 single covalent bonds, 14 hydrogen atoms
c. 7 carbon atoms, one double covalent bond, 6 single covalent bonds, 12 hydrogen atoms
d. 7 carbon atoms, one double covalent bond, 4 single covalent bonds, 16 hydrogen atoms
e. 9 carbon atoms, one double covalent bond, 6 single covalent bonds, 16 hydrogen atoms

36. The positional isomer of the above compound is ….

a. 4-methyl-1-hexene
b. 3-methyl-2-hexene
c. 2-methyl-2-hexene
d. 4-methyl-4-hexene
e. 3-methyl-4-hexene

37. Functional isomer of the above compound is ….

a. 1-methylcyclohexene
b. methylcyclohexane
c. 1-methylcyclohexane
d. cis-4-methyl-2-hexene
e. 1-heptyne

38. All isomers of C4H8 are ….
(1) cis-2-butene
(2) trans-2-butene
(3) 2-methylpropene
(4) Cyclobutane

a. (1), (2), (3)
b. (1), (3)
c. (2), (4)
d. (4)
e. (1), (2), (3), (4)

39. For a carbon atom to exhibit chirality, what feature must it possess?
a. Be attached to an oxygen atom
b. Have a multiple bond attached to it
c. Have a non-rotating C=C double bond
d. Have four different groups attached to it
e. Be attached to a highly electronega-tive atom such as fluorine, oxygen or nitrogen

40. 2-chlorobutane has an optical isomer, because ….
a. it is a hydrocarbon
b. it contains one chlorine atom
c. it consists of C, H, and Cl atoms
d. it contains 4 carbon atoms, 9 hydrogen atoms, and one chlorine atom
e. it has one asymmetrical carbon atom

41. The formula of 2-chlorobutane is ….
a. CH3CHClCH3
b. CH3CH2CH2CH2Cl
c. CH3CH2CHClCH2Cl
d. CH3CH2CHClCH3
e. CH2ClCH2CHClCH3

42. Alkanol is an organic compound which has … as a functional group.
a. – H
b. – O –
c. – OH
d. – C – C –
e. – C – O –

43. Other compounds that similar with 2-chlorobutane is ….
a. 2-butanol
b. 2-butene
c. 2-butyne
d. 1,2-butadiene
e. cyclobutane

44. The formula of 2-butanol is ….
a. CH3CHOHCH3
b. CH3CH2CHOHCH3
c. CH3CH2CH2CH2OH
d. CH3CH2CHOHCH2OH
e. CH2OHCH2CHOHCH3

45. One of the following compounds which has an asymmetrical carbon atom is ….
a. 3-pentanol
b. 2-pentene
c. 2-pentanol
d. 2-methyl-2-pentanol
e. 3-methyl-3-pentanol

46. 2-butanol has a variety of isomers. These are ….
(1) position
(2) function
(3) chain
(4) optic

a. (1), (2), (3)
b. (1), (3)
c. (2), (4)
d. (4)
e. (1), (2), (3), (4)

THE ANSWER OF HYDROCARBON PROBLEMS

2009-04-29T01:43:00.000-07:00

Organic compounds in everyday life are sugar, glucose, solar, gasoline, and LPG.
Alcohol, salt, vinegar, formalin, base, acid, and acetone.
Because C atom can form a variety of chains, i.e. opened and closed chains which can be straight and branched chains.
An aliphatic hydrocarbon is a hydrocarbon that has an opened chain; an aromatic hydrocarbon is a hydrocarbon which has a special cyclic chain, i.e. a benzene group; a branched chain is an alkyl group as a branch of a straight chain; a cyclic chain is a closed chain.
Petroleum, kerosene, and gasoline.
Alkane; General formula, CnH2n+2; molecular formula, C4H10; empirical formula, C2H5; structural formula, all atoms of C and H are separated by using a line as a single covalent bond; condensed structural formula, CH3(CH2)2CH3; line formula, only drawing a line by using a zigzag line, and skeleton formula, C-C-C-C. I hope you can do for alkene, alkadiene, alkyne, and cycloalkane.
The type of covalent bond in alkane is a single covalent bond; in alkene, besides a single bond there is one double bond; in alkadiene there are two double bonds; in alkyne there is one triple bond; and in cycloalkane there is a single bond.
A hydrocarbon in which all carbon atoms are bonded to the maximum number of hydrogen atoms is classified as saturated hydrocarbon, because the chain of C atoms has bonded a full H atoms, so it cannot bond with other H atoms. An unsaturated hydrocarbon is a hydrocarbon that doesn't contain H atoms in the maximum number, so it can be added with other H atoms.
OK students, please complete it.

THE ANSWER OF HYDROCARBON ISOMERS PROBLEMS

2009-04-29T00:17:00.000-07:00

Structural isomers are compounds which have different structural formulas, although they have the same molecular formula. Stereo isomers are compounds that have the same molecular formula and also structural formula, but have different arrangement in space.
Chain isomers are compounds which have different structural formulas because of the difference chains, although have the same molecular formula. Position isomers are compounds which have the same molecular formula, but have different structural formulas because of the difference position of their functional group. Functional isomers are compounds that have the same molecular formula, but have different structural formulas because of the difference of their functional group.
Geometric isomers are compounds which have the same molecular formula and structural formula, but have different arrangement in space, these are cis and trans isomers. Optic isomers are compounds that have the same molecular formula, structural formula, and also have the same arrangement in space, but they differ from each other only because they have different mirror images.
Alkanes only have a chain isomer, because they only have a single covalent bond among C atoms, so they don't have a functional group.
Isomers of C5H12. 1). CH3(CH2)3CH3 n-pentane; 2). (CH3)2CHCH2CH3 2-methylbutane; 3). C(CH3)4 2,2-dimethylpropane.
OK students, I hope all of you will be able to do the other problems.

HYDROCARBON ISOMERS PROBLEM

2009-04-27T02:10:00.000-07:00

There are two different types of isomers, structural isomers and stereo isomers. Explain the difference between these isomers.
Structural isomers can be classified as chain isomers, position isomers, and functional isomers. Explain the difference among these isomers.
There are two types of stereo isomers. Explain the difference between these isomers.
Alkanes only have a chain isomer. Explain the reason.
Write down the structural formulas and the names of all isomers of alkanes which have 5 (five) carbon atoms.
Alkenes have more than two types of isomers. Write down all types of alkenes isomers which have 5 (five) carbon atoms. Give the structural formulas and their names.
Cycloalkanes and alkenes which have the same number of carbon atoms are isomers. Explain the type of these isomers.
Alkynes and alkadienes which have the same number of carbon atoms are isomers. Explain the type of these isomers.
Write down the structural formulas and the names of all isomers of hydrocarbon compounds which have the same molecular formula, that is C5H8.

HYDROCARBON PROBLEMS

2009-03-31T03:40:00.000-07:00

1. You encounter many organic compounds everyday. Some organic compounds are ethanol (grain alcohol) and acetone (nail polish remover). Please, list other organic compounds which can be found around you in everyday life.

2. Hydrocarbon is one of the organic compound that mainly contains carbon and hydrogen. Which of the following compounds are not classified as hydrocarbons? Alcohol, salt, LPG, vinegar, gasoline, fat, formaline, oil, base, LNG, acid, acetone.

3. Explain the characteristics of carbon atom that can form so many compounds.

4. Please explain the following keywords concerning hydrocarbon groups : aliphatic, aromatic, branched chain, cyclic chain, closed chain, opened chain.

5. Which are the example of organic compounds that have a long chain? Petroleum, methane, glucose, kerosin, sucrose, gasoline, alcohol.

6. Write down the different formulas of hydrocarbon compounds: general formula, molecular formula, empirical formula, structural formula, condensed structural formula, line formula, and skeleton formula for each of the following compounds which have 4 C atoms each. Alkane, alkene, alkadiene, alkyne, and cycloalkane.

7. Hydrocarbon compounds can be classified as a covalent compound. However, the covalent bonds of hydrocarbons are vary. Explain the type of covalent bond in alkane, alkene, alkadiene, alkyne, and cycloalkane.

8. A hydrocarbon in which all carbon atoms are bonded to the maximum number of hydrogen atoms is classified as saturated hydrocarbon. Explain this, and also the other one.

9. Write down the name of each compounds below and give two isomers of each : n-heptane, 2,2-dimethylbutane, 2-methylhexane, cyclopentane.

10. Write down the formulas of the common name for the following alkyl groups : methyl, ethyl, propil, isopropyl, butyl, isobutyl, tert-butyl, sec-butyl.

11. A homologous series of alkanes is a series of alkane compounds in which one compound differs from a preceding one by - CH2 -. Explain by giving an example.

12. Determine the number of primary, secondary, tertiary of C atoms in CH3(CH2)3CH(CH3)(CH2)2C(CH3)3.

13. Which compound is likely to have the highest boiling point and which has the lowest one? n-butane, n-hexane, n-decane, 2-methylpropane, 3,3-dimethyloctane

14. Write the molecular formula and condensed structural formula of 2,4-dimethylpentane, then find two isomers.

15. Make a simple scheme for a type of isomerism, then give example of each. All types of isomers that you have learnt.

ACID AND BASE QUIZ

2009-03-31T03:33:00.001-07:00

1. According to the Arrhenius theory, classify the following acid and base: NH3, HBr, HNO3, NaOH HOCl, HCOOH, CH3COOH, Ca(OH)2, H2SO4, Ni(OH)2, HOClO3, Al(OH)3.
2. Organic acids contain a carboxyl group— a group that contains an acidic hydrogen that can ionize. The formula for the carboxyl group is …. Give an example.
3. From the following acids, classify as weak acid or strong one: H3PO4, HI, HCl, HNO2, HF, HNO3, H2SO3, HClO
4. Which of the following is the weakest acid?
HCl, HClO, HBr, HBrO, HI. Explain please.
5. Which of the following acids is a diprotic, weak acid?
carbonic acid, hydrochloric acid, perchloric acid, acetic acid, sulphuric acid. Explain the reason.
6. Of the following solution, … is turning blue litmus red. Why? Orange juice, lemon juice, vinegar, ammonia, table salt, alcohol 7. A common substance that contains acetic acid is …. Give the molecular formula: vinegar, ammonia water, salad oil, soap
8. Of the following, _____ is (are) a characteristic of an acid.
a. tasting sour
b. turning red litmus blue
c. turning blue litmus red
d. contain H atom in its formulae
e. producing hydrogen ions in solution
9. Of the following, _____ is(are) characteristic of a base.
a. turning red litmus blue
b. tasting bitter
c. producing hydroxide ions in solution
d. producing a solution with a pH < 7
10. When dissolved in water, salts …. a. are nonelectrolytes b. have a bitter taste c. are electrolytes d. release hydrogen ions e.release hydroxide ions
11. Write down the ionic equation. a. strong base + strong acid b. sodium oxide + water c. potassium sulfide + hydro chloric acid d. weak acid + strong base
12. Of the following, the property that most closely relates to base is(are) …. a. bitter taste b. contains hydroxide polyatomic ion c. sour taste d. salty taste
13. When an acid is dissolved in water, it usually forms ….
14. The acid used in the storage battery in your car is ….
15. The sour taste of lemons and limes is due to a substance called ….
16. The conjugate base of acetic acid (CH3COOH) is ….
17. The conjugate acid of the weak base methylamine (CH3NH2) is ….
18. Hydrazine (N2H4), formerly used as a rocket fuel, is a base. What is its conjugate acid?
19. In terms of base strength, OH- is … CH3COO-.
20. Which definition of an acid is more restrictive? In other words, which definition includes fewer substances in its definition of an acid?
21. Conjugate acid-base pair is ….
22. Which of the following pairs does not represent a conjugate acid-base pair? Explain the reason.
a. HClO4 / ClO4- b. HCl / Cl- c. H2SO4 / SO42- d. H2O / OH- e. NH3 / NH4+
23. Identify the Brønsted-Lowry acids and bases (conjugate pairs) in the following equation. (A= B-L acid; B= B-L base) HC2H3O2 + CN- = HCN + C2H3O2–
24. The conjugate of a weak base is …
25. Which of these is the weakest conjugate base? Explain.
a. NH2– b. Cl- c. C2H3O2– d. CN- e. SO42–
26. Find out acid base conjugates:
NH3 + H2O Û NH4+ + OH-
H2O + HCO3- Û H2CO3 + OH-
H2O + HCN ↔ CN- + H3O+
H2O + HSO4- ↔ SO42- + H3O+
27. Known 5 equations below: 1. H2O + NH3 ↔ NH4+ + OH- 2. H2O + HF ↔ H3O+ + F- 3. H2O + NH3 ↔ NH2- + H3O+ 4. H2O + HCN ↔ CN- + H3O+ 5. H2O + HSO4- ↔ SO42- + H3O+ Occording to Bronsted–Lowry, H2O as an acid and a base are in number ....
28. The difference between acid and conjugate base is ….
29. A substance that may act as both an acid and a base is …. 30. Which of the following would be the most basic substance in aqueous solution? Explain. HSO4-, F-, I-, Cl-, NO3- 37. Which of the following would be the most acidic substance in aqueous solution? Explain. Na+, SO42-, H2O, NH2-, NH4+
31. According to the Lewis theory, a base is ….
32. To prepare 1.0 L of a 0.100 M solution of phosphoric acid, the volume (mL) of the concentrated solution (15 M) which needed is ….
32. Barium hydroxide is a strong base. Compute [Ba2+] and [OH-] for a solution that is prepared by dissolving 6.0 x 10-2 mole of barium hydroxide in 500.0 mL of water. (Ar Ba = 137.33, O = 16.00, H = 1.008)
33. Calculate the [ClO4-], and [H3O+] in an aqueous solution containing 0.025 moles of HClO4 in 500.0 mL of water.
34. The normality of a solution of sulfuric acid that is 0.200 M is ….
35. A bottle of wine vinegar contains 6.5HC2H3O2 by mass. If vinegar has a density of 1.03 g/ml, how many grams of HC2H3O2 are in a 400 ml bottle?
36. Glacial acetic acid has a density of 1.05 g/ml. If 46.2 of HC2H3O2 will dissolve in 1.0g of water, the molarity of the solution is ….
37. Glacial acetic acid is a saturated solution. If 46.2 g of HC2H3O2 will dissolve in 1.0g of water, the mass percent acetic acid is ….
38. When 25.00 mL of 0.250 M potassium hydroxide solution reacts with 20.00 mL of 0.500 M sulfuric acid solution, _____ moles of water will be produced.
39. How many mL of water must be added to 50 mL of 0.100M HCl to dilute it to 0.033M?
40. What is the normality of 100g of H2SO4 dissolved in 1L of H2O?
40. How many millimoles of H+ are there in 50.0 mL of 0.10 M HCl?
41. How many mmol OH- are there in 20.0 mL of 0.010 M Ba(OH)2?
42. What is the molarity of 250.0 mL of a solution which contains 25.0 mmol of H+?
43. Given the following Ka values, determine which species is the strongest base and give the reason. H2SO3 1.2 x 10-2 HNO2 4.5 x 10-4 HCNO 3.5 x 10-4
44. The Ka values for HCNO and HNO2 are 2.2 x 10-4 and 4.5 x 10-4 respectively. Therefore it follows the HCNO is a acid than HNO2 and CNO- is a _____ base than NO2-.
45 The Ka values for HS- and HPO42- are 1.2 x 10-13 and 4.8 x 10-13 respectively. Therefore it follows the HS- is a _____ acid than HPO42- and S2- is a _____ base than PO43-.
46. Based upon the following values of Ka, place the acids in order from weakest to strongest …. HCN (Ka = 6.2 x 10-10) HCOOH (Ka =1.78 x 10-4) HC2H3O2 (Ka = 1.8 x 10-5) HNO2 (Ka = 4.6x10-4)
47. Which of the following is not true for the dissociation of a strong acid? Explain.
a. The equilibrium lies far to the right
b. equilibrium lies far to the left
c. [H+] >> [HA]
d. Ka is large
e. The conjugate base will be weak
58. What change will be observed for the following reaction if a few drops of NaOH are added?
HNO2+H2O NO2-+H3O+
a. an increase in the fraction of acid dissociated
b. a decrease in the fraction of acid dissociated
c. no change in the fraction of acid dissociated
59. What change will occur for the following reaction if a few drops of HCl are added?
CH3CO2H + H2O --> CH3CO2- + H3O+
60. Given Ka values of 1.8 x 10-4 and 6.8 x 10-4 for HCO2H and HNO2 respectively, the equilibrium constant for the following reaction is ….
HCO2- + HNO2 --> HCO2H + NO2-
61. Given Ka values of 1.0 x 10-10 and 6.8 x 10-8 for C6H5OH and C5H5NH+ respectively, the equilibrium constant for the following reaction is ….
C6H5O- + C5H5NH+
C6H5OH + C5H5N
62. Given Ka values of 5.6 x 10-10 and 1.7 x 10-5 for NH4+ and CH3CO2H respectively, calculate the equilibrium constant for the following reaction.
NH4+ + CH3CO2- --> NH3 + CH3CO2H
63. What is the hydronium ion concentration of a 0.380 M acid solution of an acid whose ionization constant is 1.58x10-9
64. What is the hydronium ion concentration of a 0.1 M solution of Zn2+ solution of zinc perchlorate? The acidity constant of the following reaction is 3 x 10-10.
Zn2+(aq) + 2 H2O --> Zn(OH)+(aq) + H3O+
65. What is the hydronium ion concentration of a 0.02 M solution of Cu2+ solution of copper(II) perchlorate? The acidity constant of the following reaction is 5x10-9
Cu2+(aq) + 2 H2O --> Cu(OH)+(aq) + H3O+
66. What is the ionization constant of an acid if the hydronium ion concentration of a 0.400 M solution is 1.40 x 10-4 M?
67. What is the acidity constant for the following reaction given that the hydronium ion concentration of a 0.04 M solution of Ni2+ solution of nickel(II) perchlorate is 4.5x10-6?
Ni2+(aq) + 2 H2O --> Ni(OH)+(aq) + H3O+

BUFFER SOLUTION QUIZ

2009-03-31T03:31:00.000-07:00

1. Calculate the pH of the following mixtures.
a. 1.0 M NH3/1.0 M NH4Cl
b. 1.0 M HCl/1.0 M NaCl
c. 1.0 M NaOH/1.0 M NaCl
d. 1.0 M KCl/1.0 M KOH
e. 1.0 M H2SO4/1.0 M K2SO4
2. A buffer solution may be prepared by using a strong acid and a salt containing ….
3. A(n) _____ solution is one that resists change in pH when an acid or base is added to it.
4. Calculate pH of the following mixtures.
a. 1.0 M NaOH/1.0 M NaCl
b. 1.0 M HCl/1.0 M NaCl
c. 1.0 M HF/1.0 M KF
d. 1.0 M KCl/1.0 M CH3COOH
e. 1.0 M HNO3/1.0 M KNO3
5. A buffer solution must contain (at least) ….
6. Which of the following combinations will produce a buffer solution? Give the reason.
a. HCl and Cl-
b. NaCl and NaOH
c. SO42- and SO32-
d. HC2H302 and NaC2H3O2
e. HNO3 and HCl.
7. The Ka values for HF and HNO2 are 6.8 x 10-4 and 4.5 x 10-4 respectively. Therefore it follows the HF is a _____ acid than HNO2 and F- is a _____ base than NO2-.
8. The Ka values for HSO4- and H2PO4- are 1.2 x 10-2 and 6.3 x 10-8 respectively. Therefore it follows the HSO4- is a _____ acid than H2PO4- and SO42- is a _____ base than HPO42-.
9. alues for HPO42- and HSO3- are 4.8 x 10-13 and 6.3 x 10-8 respectively. Therefore it follows the HPO42- is a _____ acid than HSO3- and PO43- is a _____ base than SO32-
10. What change will occur for the following reaction if a few drops of HCl are added?
CH3CO2H + H2O == CH3CO2- + H3O+
11. What change will be observed for the following reaction if a few drops of NaOH are added?
HNO2 + H2O == NO2- + H3O+
12. What change will occur for the following reaction if the hypochlorous acid solution is diluted from 0.1 to 0.01 M?
HOCl + H2O == OCl- + H3O+
13. What is the hydronium ion concentration of a solution of 0.480 M acid and 0.680 M of its conjugate base if the ionization constant is 5.78 x 10-7?
14. What is the hydronium ion concentration of a solution of 0.700 M acid and 0.440 M of its conjugate base if the ionization constant is 3.59 x 10-8?
15. What is the hydronium ion concentration of a solution of 0.720 M acid and 0.240 M of its conjugate base if the ionization constant is 4.38 x 10-6?
16. What is the pH of a solution of 0.81 M acid and 0.35 M of its conjugate base if the ionization constant is 5.45 x 10-8?
17. What is the hydronium ion concentration of a solution of 0.720 M acid and 0.240 M of its conjugate base if the ionization constant is 4.38 x 10-6?
18. What is the pH of a solution of 0.81 M acid and 0.35 M of its conjugate base if the ionization constant is 5.45 x 10-8?
19. What is the pH of a solution of 0.28 M acid and 0.73 M of its conjugate base if the ionization constant is 3.75 x 10-9?
20. What is the pH of a solution of 0.49 M acid and 0.29 M of its conjugate base if the ionization constant is 5.92 x 10-8?
21. What is the pH of a solution of 0.17 M acid and 0.81 M of its conjugate base if the pKa = 8.62?
22. What is the pH of a solution of 0.28 M acid and 0.54 M of its conjugate base if the pKa = 7.93?
23. What is the pH of a solution of 0.65 M acid and 0.51 M of its conjugate base if the pKa = 5.30?
24. The toxic compound 2,4-dinitrophenol (used in biological research to inhibit energy production in cells) has Ka = 1.1 x 10-4 M. In an experiment, a solution of 2,4-dinitrophenol was prepared with the pH adjusted to 7.40. Calculate the ratio of the concentrations of the dissociated ion to the undissociated acid.
25. Acetylsalicylic acid (aspirin) can have a serious effect on the stomach. Only the undissociated acid can cross the stomach lining. Calculate the ratio of acid to dissociated ion when the pH of the stomach is 2.00. The Ka of this acid is 2.75 x 10-5.
26. Uric acid is one metabolic end product and is excreted from the body in urine. The acid dissociation constant of uric acid is Ka = 4.0 x 10-6 M. The pH of a urine sample is 6.00. What is the ratio of urate ion to uric acid in the urine?
27. A buffer solution is prepared by the addition of 20.0 grams of HF and 21.0 grams of NaF to enough water to make 1.000 L of solution. The Ka of HF is 7.2 x 10-4. What is the pH of this solution?
28. Which of the following pairs of compounds dissolved together in aqueous solution would NOT make a good buffer solution? Why?
a. HNO3/NaNO3
b. H3PO4/NaH2PO4
c. H2CO3/KHCO3
d. HCN/KCN
29. We desire to make a buffer solution with a pH of 9.2. Which combination of compounds would be the best to use? Refer to the table of bases given.
a. HAc/NaAc
b. NH3/NH4Cl
c. HCl/NaCl
d. pyridine/pyridine chloride
30. A solution is prepared which is 1.0 M acetic acid. What would happen to the pH of this solution if potassium acetate were added to the solution?
31. An aqueous solution of NH3 is in equilibrium. Suppose a gram of NH4Cl is added to the solution, and it is allowed to come to a new equilibrium. What will happen to the pH as a result of addition of NH4Cl?
32. A buffer solution is 0.10 M HAc (acetic acid) and 0.10 M NaAc (sodium acetate) and we have 1.000 Liter of it.
What is the pH after 0.010 moles of HCl are added to this solution?
33. A buffer solution has a pH = 5.5. What is the [H3O+] concentration?
34. An indicator symbolically given as HIn can be in two different forms: as HIn (red) or as In- (yellow). The pKa of the indicator is 4.0. What will be the color of the indicator in a solution which has a pH = 7?
c. a color intermediate between yellow and red
35. Calculate the pH of a solution which is formally 0.50 M HAc and 0.10 M NaAc.
36. A solution is prepared which is 1.0 M HOCl and 1.0 M NaOCl. What is its pH?
37. A solution is prepared which is 1.0 M HCl and 1.0 M NaCl. What is its pH?
38. A 1.00 Liter buffer solution is prepared which is 1.0 M in HAc and 1.0 M in NaAc. What would be the pH after 10.0 grams of NaOH were added to the solution?
39. What is the H+(aq) concentration of 0.10 M NaAc(aq)?
40. The indicator bromocresol green, given symbolically as HIn, can be in two different forms: as HIn the color of the indicator is yellow, as In- the color of the indicator is blue, and an equilmolar mixture of the two species is green. The Ka of the indicator is 2.5x10-5. What will be the color of the indicator in a solution which has a pH = 3.8?
41. A solution is prepared in which 1.0 mole of NaNO2 and 1.5 moles of HNO2 are added to a liter of aqueous solution. What is the pH of this solution?
a42. Suppose 3.65 grams of HCl are added to the solution in #6. What will be the new pH of the solution?
43. Which salt would produce a solution with a pH significantly greater than 7.0?
a. NH4Cl
b. NaOCl
c. KCl
d. NaI
e. K2SO4
44. What is the [H+] concentration of a 0.500 M solution of NaF?
45. Calculate the pH of a solution which is 2.0 M NH3 and 2.0 M NH4Cl.
46. What is the Kb of the NO2- species?
47. A flask originally contains 100.0 mL of 0.500 M aqueous HAc solution. To this solution is added 50.0 mL of 0.400 M NaOH solution. Calculate the pH of the resulting solution.
48. When a weak acid is titrated with a strong base the following pH curve is obtained. What is the approximate pKa of the weak acid?

HYDROLISIS QUIZ

2009-03-31T03:28:00.000-07:00

1. The following salts are dissolved in water. Write down the hydrolysis equation and estimate the pH.
a. Na2CO3
b. KCN
c. NaNO2
d. NH4Cl
e. NaF
2. The Ka of HNO2 is 7 x 10-4. What is the Kb of its conjugate base, NO2-?
3. What is the hydrolysis constant of the OBr- ion? The ionization constant of HOBr is 2.0 x 10-9.
4. What is the hydroxide ion concentration of 0.110 M OCl-? The ionization constant of HOCl is 3.0 x 10-8.
5. What is the hydronium ion concentration in a 0.440 M OI- solution? (Ka HOI = 2.0 x 10-11)
6. What is the hydronium ion concentration of a 0.04 M solution of Ni2+ solution of nickel(II) perchlorate? The acidity constant of the following reaction is 5x10-10.
Ni2+(aq) + 2 H2O == Ni(OH)+(aq) + H3O+
7. What is the hydronium ion concentration of a 0.1 M solution of Zn2+ solution of zinc perchlorate? The acidity constant of the following reaction is 3 x 10-10.
Zn2+(aq) + 2 H2O == Zn(OH)+(aq) + H3O+
8. Consider the properties of the following salts and predict the pH
CoBr2, (NH4)2S, CaBr2, NH4Br, KHSO4, NaCN, NaNO3, K2S, K2CO3
9. What is the pH of a 0.10 M C6H5O- solution? The Ka of C6H5OH is 1.0x10-10
10. Sodium propionate, NaC3H7O2, is used as a food preservative. Calculate the pH of a 0.20 M solution of sodium propionate given Ka = 3.4 x 10-5 for propionic acid.
11. What is the pH of a 0.68 M CN- solution? (Ka of HCN = 4.4 x 10-10)
12. What is the pH of a 0.44 M OI- solution? (Ka of HOI=2.0x10-11)
13. What is the molarity of a potassium hydroxide solution if 50.0 mL of it neutralizes 25.0 mL of a .250 M solution of sulfuric acid?

pH OF ACID AND BASE QUIZ

2009-03-31T03:25:00.000-07:00

1. The pH of water at 298K is ….
2. HCl(aq) 0,01 M 200 mL. The pH of this solution is ….
3. If 2 g of NaOH(s) is added to water and the volume of solution is 500 mL, the pH is …. (Ar Na=23,O=16,H=1)
4. HCl(aq) 0,1 M 50 mL + HCl 0,3 M 50 mL. The pH is ….
5. NaOH(aq) 0,1 M 50 mL + Ba(OH)2(aq) 0,1 M 50 mL. The pH is ….
6. The pOH of a solution that has [H+] = 2 x 10-6M is ….
7. A solution of 0.01 M niacin has a hydronium ion concentration of 4 x 10-4 M. The pH of the solution is ….
8. The pH of an aqueous solution which is 0.0030 M HClO4 is ….
9. The hydroxide ion concentration of the oceans is about 1 x 10-6. What is the pH?
10. The hydroxide ion concentration of lemon juice is about 2.0 x 10-12. What is the pH?
11. The pH of human muscle fluids is 6.80. The [H3O+] in muscle fluid at 25oC is ….
12. The pH of the contents of the human stomach is about 1.0. The value of [H3O+] in the stomach at 25oC is ….
13. The pH of a saturated solution of Mg(OH)2 is 10.50. The molarity of the magnesium ion is ….
14. A solution of morphine (a narcotic) has a pH of 9.7. The [OH-] is ….
15. The pOH of a 0.001 M solution of ammonia is _____ the pOH of a 0.001 M solution of potassium hydroxide.
16. The pOH of an NH3 solution is ….
17. If the pH of a solution is equal to 11, the solution is ….
18. As the [H+] increases … the pH of base ....
19. A solution whose pH is equal to 4.0 has a hydrogen ion concentration of ….
20. If the pH of a solution is equal to 3, the hydroxide ion concentration is ….
21. The pH of a solution whose hydroxide ion concentration is 0.0010 M is ….
22. A solution whose pH is equal to 12 … is turned litmus ....
23. A solution with a pH equal to 2 has a pOH equal to ….
24. The pH of a solution whose hydronium ion concentration is 1 x 10-5 M is ….
25. A solution whose pOH is equal to 6 has a hydrogen ion concentration of ….
26. In a particular solution, [H+] = 2 X 10-9M. The pH is ….
27. A solution has [H+] = 2 X 10-4M. How many significant figures does the pH have?
28. The [OH-] in a solution that has a pH of 5.40 is ….
29. A solution has [HC2H3O2] = 1.5 X 10-2M. The pH of this solution will be _____ the pH of a 1.5 X 10-2M solution of HCl.
30. What concentration of HOCl (Ka = 4 x 10-8) has the same pH as that of 3 x 10-4 M HNO3?
31. What is the pH of a sample of gastric juice whose hydronium ion concentration is 5 x 10-2 M?
32. The pH of the world's oceans is 8. The [H3O+] in the ocean is ….
33. What is the pH of human muscle fluid in which the hydronium ion concentration is 2 x 10-7 M?
34. A vinegar has a hydroxide ion concentration of 1 x 10-11 M. What is the pH of the vinegar?
35. The hydroxide ion concentration of lemon juice is about 2.0 x 10-12. The pH is ….
36. A detergent solution has a pH of 11.7. What is the [OH-]?
37. The pH of a saturated solution of Ca(OH)2 is 11. The molarity of the calcium ion is ….
38. The pH of indicators.
Indicators pH Color
MO 3,2 - 4,4 red - yellow
MR 4,4 - 6,3 red - yellow
BTB 6,0 - 7,6 yellow - blue
PP 8,2 – 10,0 colorless - red
The correct color when these indicators are added to HClaq) are ....
39. X(aq) is turning blue litmus to red color. If it is used MR, the color becomes red. The correct properties of this solution are ....
40. The pH of a solution is about 7. The correct statement of this solution is :
a. PP, the solution becomes ....
b. BTB, the solution becomes ....
c. MR, the color changes to ....
d. MO, the color changes to ....
e. red litmus becomes ....

CHEMISTRY IN THE DAILY LIFE CONTEXT

2009-03-23T08:47:00.000-07:00

Students, I hope this blog can be used as a media for our communication about chemistry lessons, so step by step, gradually chemistry will be easier for you during your school day. Please, follow this blog continuously. Every moment you need my help, you can ask me. You know that chemistry is around the world; when we look at around, everything is chemistry. So in the context of daily life, hopefully, chemistry will be easier for you to learn.
In chemistry lessons, you will use your experiences in your daily life about chemistry processes, for example washing, cooking, using fuel, about pollution, and metabolism. All of these will be used by teachers as concrete things to guide you step by step moving to the abstract theories that the important concepts which have to be learnt.
For example, in learning aqueous solution, you have to think carefully about dissolving sugar into water. After you mix sugar and water, you cannot see the sugar, but the taste of this solution is sweet as a taste of sugar itself. So the molecules of sugar have already mixed with the molecules of water. Among the water molecules there are a space that the sugar molecules can stay together with water molecules homogeneously. Before mixing, the phase of sugar is solid and the phase of water is liquid. After mixing, they come together in one phase, that is liquid. That is why you cannot see the sugar anymore in the aqueous solution. Aqueous solution is the solution in which water is a solvent.