carbon compund

1. What is the general formula of alkanes?

A C_nH_2n

B C_nH_2n+2

C C_nH_2n+1OH

D C_nH_2n+1COOH

2. Which of the following statement is the physical property of alcohol?

A It smells like vinegar.

B It is soluble in water.

C It conducts electricity.

D It has high boiling point.

3. A structural formula is the chemical formula that shows the

A simplest ratio of elements in a molecule.

B number of moles of element in a molecule.

C actual number of each type of element in a molecule.

D presence of each type of element and how the atoms of the elements in a molecule are bonded.

4. What is meant by unsaturated hydrocarbons?

A Organic compounds containing carbon and hydrogen only.

B Hydrocarbons contain at least one carbon-carbon double bond.

C Hydrocarbons consist of entirely of carbon-carbon single bonds.

D Organic compounds in which some or all of the hydrogen atoms can be replaced by other atoms.

5. Which of the following statement is not true about the members of a homolog series?

A They have the same functional group.

B They exhibit the same physical properties.

C They exhibit the same chemical properties.

D They can be represented by a general formula.

6. Which of the following is a natural polymer?.

A Polyethene

B Polystyrene

C Polypropene

D Polyisoprene

7. The equation shows an esterification reaction.

CH₃OH + CH₃COOH CH₃COOCH₃ + H₂O

What is the function of concentrated sulphuric acid in producing methyl ethanoate?

A To dry the ethanol.

B To speed up the reaction.

C To absorb water produced.

D To increase the temperature of the reaction.

8. The empirical formula of a hydrocarbon is CH₂. Its relative molecular mass is 56. What is the molecular formula of the hydrocarbon?

[Relative atomic mass: H, 1; C, 12 ]

A C₃H₈

B C₄H₈

C C₄H₁₀

9. Acidic properties of carboxylic acids are due to the presence of

A carbon group

B carboxyl group

C functional group

D carbon-carbon double bond

10. All members of a homologous series have similar

A structural formula

B molecular formula

C physical properties

D chemical properties

11. Explain why combustion of hexene, C₆H₁₂ produce more soot than hexane, C₆H₁₄.

[Relative atomic mass: H,1; C,12]

12. Draw the structural formulae for the organic compounds below:

(a) n-butane, C₄H₁₀

(b) pent-2-ene, C₅H₁₀

(c) propan-1-ol, C₃H₇OH

(d) propanoic acid, C₂H₅COOH

(e) ethyl ethanoate, CH₃COOC₂H₅

13. Organic compounds are classified into different

A group

B period

C chemical reaction

D homologous series

14. Which of the following is a homologous series?

A Alcohol

B Halogen

C Noble gas

D Alkali metal

15. The equation represents the combustion of propanol in excess oxygen.

2C₃H₇OH(l) + 9O₂(g) à 6CO₂(g) + 8H₂O(l)

From the equation above, 2 moles of propanol produce 6 moles of carbon dioxide gas. What is the volume of carbon dioxide gas that is produced at room conditions when 0.2 mol of propanol is heated in excess oxygen?

[1 mol of any gas occupies 24dm³ at room conditions]

A 4.8 dm³

B 7.2 dm³

C 14.4 dm³

OXIDATION AND REDUCTION

1. An oxidation reaction is a process that involves the

A loss of oxygen

B gain of electrons

C loss of electrons

D gain of hydrogen

2. What is a redox reaction?

A A reduction reaction

B An oxidation reaction

C Both oxidation and reduction reaction

3. An oxidizing agent is a substance that

A donates oxygen

B accepts electrons

C donates electrons

D donates hydrogen

4. Which of the following is a half-equation?

A Cu²⁺ → Cu

B Cu²⁺ + 2e → Cu

C Zn + Cu²⁺ → Zn²⁺ + Cu

D Zn + CuCl₂ → ZnCl₂ + Cu

5. What is metal corrosion?

A Change of metal to its ion

B Change of ion to its metal atom

6. Which of the following substances is a reducing agent?

A Zinc

B Chlorine

C Potassium dichromate(VI)

D Potassium manganate(VII)

7. Which of the following is the most electropositive metal?

A Cu

B Mg

C Na

D Zn

8. Which of the following substances cannot be reduced by carbon, C?

A Zinc oxide, ZnO

B Iron(III) oxide, Fe₂O₃

C Copper(II) oxide, CuO

D Aluminium oxide, Al₂O₃

9. Which of the following cells can be recharged?

A Dry cell

B Alkaline cell

C Mercury cell

D Nickel-cadmium cell

10. Which of the following methods is not used in rust prevention?

A Making iron into alloys

B Galvanizing iron with zinc

C Attaching iron with copper

D Electroplating iron with silver

11. What is the oxidation number for iron in iron(II) chloride?

A +1

B +2

C +3

D +4

12. Which of the following is a redox reaction?

A Na₂O + H₂O → 2NaOH

B NaOH + HCl → NaCl + H₂O

C 2Na + 2H₂O → 2NaOH + H₂

D NaCl + AgNO₃ → AgCl + NaNO₃

13. Which of the following undergoes oxidation reaction?

A Zn changes to Zn²⁺ ion

B MnO₄^- ion changes to Mn²⁺ ion

C Cr₂O₇^2- ion changes to Cr³⁺ ion

D Br₂ molecule changes to Br^- ion

14. The equation shows a displacement reaction.

Zn + Cu²⁺ → Zn²⁺ + Cu

Which of the following acts as a reducing agent?

A Cu

B Zn

C Cu²⁺

D Zn²⁺

15. The equation shows a redox reaction,

Cl₂ + H₂S → S + 2HCl

What is the change in the oxidation number for sulphur?

A +2 → 0

B -2 → 0

C +2 → -1

D -2 → -1

16. The ionic equation shows the displacement of bromine by chlorine.

Cl₂ + 2Br^- → 2Cl^- + Br₂

Which of the following is true?

A Chlorine is oxidized

B Chlorine is a reducing agent

C Bromide ion donates electron

D Bromide ion is an oxidizing agent

17. The equation shows the conversion of iron(III) ion into iron(II) ion.

2Fe³⁺ + Zn → 2Fe²⁺ + Zn²⁺

Which of the following substances can be used to replace zinc, Zn?

A KI

B Cl₂

C KMnO₄/H⁺

D K₂Cr₂O₇/H+

18. The figure shows the set-up of apparatus to investigate the reactions between bromine and iron(II) sulphate solution.

What can be observe after a few minutes?

A Grey solid is formed

B Bromine water changes from colourless to brown

C Iron (II) sulphate solution changes from green to yellow.

D ron (II) sulphate solution changes from yellow to colourless

19. The figure shows the set-up of the apparatus used to study the transfer of electron at a distance.

What is substance P?

A Iodine solution

B Iron(II) chloride solution

C Iron(II) sulphate solution

D Potassium manganate(VII) solution

20. Which of the following mixtures can react when they are heated strongly?

A Carbon and zinc oxide

B Copper and iron oxide

C Copper and lead oxide

D Carbon and magnesium oxide

21. What is the oxidation number of chromium, Cr in Cr₂O₇^2- ?

A +2

B +3

C +6

D +7

22. Which of the following represents the oxidation number of nitrogen in the various oxides of nitrogen?

	NO	NO2	N2O4
A	+1	+2	+2
B	+1	+1	+2
C	+2	+4	+4
D	+2	+4	+8

23. The equation shows a redox reaction.

2X + Y ²⁺ → 2X ⁺ + Y

Based on the equation, which of the following is true?

A The oxidation number of X change from 0 to +1.

B The oxidation number of X changes from 0 to +2.

C The oxidation number of Y changes from +1 to 0.

D The oxidation number of X and Y does not change.

24. The half-equation shows an oxidation reaction.

Based on the equation, what is meant by oxidation reaction?

A Electrons are donated by iodine.

B Electrons are received by iodine.

C Electrons are donated by iodide ions.

D Electrons are received by iodide ions.

25. The ionic equation shows a redox reaction.

P (s) + Q²⁺(aq) P²⁺ (aq) + Q (s)

Which of the following statement is true?

A Q²⁺ is oxidized.

B P donates electrons

C P is an oxidizing agent

D Q²⁺ is a reducing agent

26. The figure shows the set-up of the apparatus for the electrolysis of copper(II) chloride solution.

After one hour, it is found that the intensity of the blue solution decreases.

Which of the following explains the observation?

A Cl⁻ ion is discharged at the anode

B OH⁻ ion is discharged at the anode

C H⁺ ion is discharged at the cathode

D Cu²⁺ ion is discharged at the cathode

27. The figure shows a chemical cell.

The reaction that occurs is given by the equation:

Zn (s) + CuSO₄ (aq) ZnSO₄ (aq) + Cu (s)

Which of the following is correct about the cell?

A Hydrogen gas is produced.

B Zinc is oxidized to zinc ion, Zn²⁺.

C Copper is oxidized to copper(II) ion, Cu²⁺.

D Electrons flow from the copper plate to the zinc plate.

28. The table shows two displacement reactions involving metals X, Y and Z.

Reaction I	X + Y 2+ (aq) Y + X2+(aq)
Reaction II	Z + X2+(aq) Z2+ (aq) + X

What is the decreasing order of electropositive for metals X, Y and Z in the electrochemical series?

A X,Y,Z

B X,Z,Y

C Y,X,Z

D Z,X,Y

29. The figure shows an experiment to study the effect of different metals in contact with iron nail on rusting.

After one week, blue spots are seen in test tube B but not in test tube A.

What inference can you make from the observation?

A Iron(II) ions are formed in test tube A.

B Corrosion of iron occurs in test tube A .

C Zinc prevents the iron nail from rusting.

D Copper prevents the iron nail from rusting.

30. The table below shows the observation when the mixture of metal and oxide metal are heated strongly.

Mixture	Observation
Metal Q + oxide P	Glows brightly
Metal R + oxide P	No changes

Based on the observation, which of the following is the correct order of reactivity for the metal of P, Q, and R in the increasing order?

A P, Q, R

B Q, P, R

C R, P, Q

D R, Q, P

31. The equation shows the conversion of Fe²⁺ to Fe³⁺.

Fe²⁺ → Fe³⁺ + e

Explain why Fe²⁺ is oxidized.

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………..

32. The equation shows a redox reaction.

Cu + 2Ag⁺ → Cu²⁺ + 2Ag

Explain why Cu acts as an oxidizing agent.

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

33. The figure shows the set-up of apparatus to investigate the effect of metal on rusting.

The results of the experiments are shown in the table.

Set	Metal attached to iron nail	Observation
I	Magnesium	No blue colour formed
II	Copper	Blue colour formed

Explain the difference in observations for both sets of experiments.

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

34. Study the two chemical equations.

Equation I : Na₂SO₄ + Ba(NO₃)₂ → BaSO₄ + 2NaNO₃

Equation II : Mg + CuSO₄ → MgSO₄ + Cu

From the equations, choose one that is a redox reaction and explain your answer.

Equation : ……………………………………………………………………………………….

Explanation : ……………………………………………………………………………………

…………………………………………………………………………………….

35. The figure shows two electrochemical cells.

(a) State the difference in the energy change in the two electrochemical cells.

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

(b) State the different products formed at the positive terminals in both cells.

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

Listen carefully to the text read by the teacher. Answer questions 36 and 37.

36. Which of the following statement is true?

A Bromide ion is a reducing agent.

B Oxidation process occurs at cathode

C Positively-charged lead(II) ions move to anode.

D lead (II) ions lose electrons to become metallic lead.

37. Which of the following substances is an oxidizing agent?

A Lead metal.

B Bromine gas.

C Lead (II) ions.

D Bromide ions.

Listen carefully to the text read by the teacher. Answer questions 38 and 39.

38. Which of the following statement is true?

A Bromine is an oxidizing agent.

B Bromine molecules are oxidized.

C The colourless bromine water turns brown.

D Bromine is less electronegative than iodine.

39. Which of the following substances undergoes oxidation?

A Iodine.

B Bromine.

C Iodide ion.

D Bromide ion.