FORM 4 CHAPTER 5 ENERGY & CHEMICAL CHANGES

1. Which of the following is a physical change?A Boiling of waterB Putting a piece of calcium into waterC Heating of magnesium and sulphur D Heating of zinc carbonate

2. Which of the following is a chemical change? A Cooling steam to get water B Mixing copper chloride solution and sodium hydroxide solution C Heating ammonium chloride D Heating wax in a test tube

3. Which of the following characteristics indicate physical changes of a substance? I No new substance is formed II May change back into the original state III Involves a lot of energy change A I and II only B I and III only C II and III only D I, II and III

4. Which of the following is true about the endothermic reaction? A Heat is released into the environment. B The reactants have less energy than the products of the reaction. C The temperature of the surrounding rises. D Respiration in the body cells is one form of the endothermic reaction.

5. Which of the following metal oxides can be reduced by heating with carbon? I Aluminium oxide II Iron oxide III Zinc oxide A I and II only B I and III only C II and III only D I, II and III

6. The diagram below shows a chemical reaction .

Dilute sulphuric acid Magnesium What is the gas released?

A Nitrogen dioxide B Carbon dioxide C Hydrogen D Oxygen

7. Which of the following metals can oxidise faster than lead in the air? AStanum B Copper C Mercury D Silver

8. The diagram shows the position of metal X in te reactivity series of metals.

Metal X Carbon Reactivity increase Copper What is metal X? A Zinc C Lead B Iron D Magnesium

9. Which of the following shows the order of reactivity of metals beginning with the most reactive metal? A Calcium, sodium, zinc, magnesium B Sodium, calcium, magnesium, copper C Magnesium, calcium, zinc, sodium D Sodium, magnesium, copper, lead

10. What type of battery is used in a car? A Lead-acid accumulator B Alkaline battery C Nickel-cadmium battery D Silver-oxide mercury battery

11. Which of the following represents the positive electrode of the dry cell?

A P C R B Q D S

12. The diagram below shows the structure of a dry cell.

P

Q

R

S

Which parts labelled A, B, C or D is the electrolyte ammonium chloride paste? 13. What is the advantage of a dry cell compared to an acid-lead accumulator? A The voltage is higher B It has longer lifespan C The current is more stable D The electrolyte does not spill

14. Which metal can be extracted from its ore through the process of reduction using carbon? A Tin B Calcium C Aluminium D Magnesium

15. Metals that have to be extracted by electrolysis are I iron II aluminium III sodium A I only C I and II only B III only D II and III only 16. The process of electrolysis is used to I coat the metal II purify the metal III extract the metal from its ore A III only B I and II only C I and III only D I, II and III

17. Which of the following are weaknesses of a lead-acid accumulator? I Heavy

II Its electrolyte spills over easily III Cannot be recharged A II only B I and II only C I and III only D II and III only

18. Which of the following does not need the presence of light?

Metal cap

A

D

B

C

A Photosynthesis B Transpiration C Photography D Decomposition of chemicals

19. The diagram shows an electroplating of an iron spoon.

What is solution X? AAluminium nitrate B Copper(II) sulphate C Silver nitrate DIron(II) sulphate

20. A chemical reaction which releases heat to the surroundings is called Aan oxidation reaction B an exothermic reaction C an endothermic reaction Da decomposition reaction

Iron spoon

Silver

Solution X

Structured Questions

1. The diagram below shows a process carried out in a green plant.

The following word equation describes the process.

Water + carbon dioxide X + Y P pigment

a) What are X and Y?

___________________________________________________________________________

b) i) Name the P pigment needed for the reaction to occur.

_________________________________________________________________________

ii) State the function of P pigment.

_________________________________________________________________________

c) i) Name the process that is involved in the chemical reaction above.

_________________________________________________________________________

ii) State two factors which influence the process in c) i).

_________________________________________________________________________

Light

2. The diagram below shows an electrolysis experiment for copper(II) chloride solution, using electrodes X and Y.

Copper(II) chloride

a) i) Anode electrode is represented by ____________________ .

ii) Cathode electrode is represented by __________________ .

b) If you wish to electroplate an iron spoon with nickel, what should you use as

i) cathode? _________________________________

ii) anode? _________________________________

iii) electrolyte? ________________________________

c) What are the advantages of using metal electroplate?

___________________________________________________________________________

Y X

AnswersObjective questions

1. A 11. B

2. B 12. C

3. A 13. D

4. B 14. A

5. C 15. D

6. C 16. D

7. A 17. B

8. A 18. B

9. B 19. C

10. A 20. B

Structured questions

1 (a) X = glucose Y = oxygen (b) (i) chlorophyll (ii) Absorbs sunlight (c) (i) Photosynthesis (ii) Light intensity/ water/ temperature/ carbon dioxide concentration

2 (a) (i) X (ii) Y (b) (i) Iron spoon (ii) Nickel

(iii) Nickel salt solution (c) can withstand corrosion