RATE OF REACTION

1. The collisions that are successful in producing a chemical reaction are called A effective collisionsB ineffective collisionsC successful collisionsD unsuccessful collisions

2. The figure shows the energy profile of a reaction.Which of the following options A, B, C, and D in the figure shows the activation energy?

3. Which of the following alters the rate of a chemical reaction but remains chemically unchanged at

the end of a reaction?A ProductB CatalystC Reactant

4. The number of collisions per second that will result in a reaction is known as collision theoryA effective collisionB effective collision frequencyC ineffective collision frequency

5. Which of the following equations gives the meaning of rate of reaction?

A

B

C

D

6. Which of the following statement is true about the collision theory?

A

B C

D

Energy

Products

Reactants

Reaction path

A All collisions produce a reaction.B The increase in the activation energy will increase the rate of reaction.C The increase in the effective collision frequency will increase the rate of reaction.D The increase in the effective collision frequency will increase the quantity of the product

formed.

7. Which of the following does not affect the rate of a reaction?A TemperatureB Size of a reactantC Volume of solutionD Concentration of solution

8. Which of the following is not the characteristic of catalyst?A Are specific in their actions.B Increase the quantity of products.C Do not change chemically after a reaction.D Are required in small amount to affect the rate of reaction.

9. The equation shows the reaction between calcium carbonate and dilute hydrochloric acid.CaCO3 (s) + 2HCl (aq) CaCl2 (aq) + H2O (l) + CO2 (g)

After 60 seconds, the volume of gas produced is 85 cm3. Calculate the average rate of reaction in the unit of cm3s-1.A 0.71B 1.42C 25.00D 5100.00

10. When the concentration of a solution increases, the rate of reaction also increases.Which of the following solutions will produce the highest rate of reaction between magnesium and dilute hydrochloric acid?A 50 cm3 of 0.10 moldm-3 HClB 50 cm3 of 0.15 moldm-3 HClC 50 cm3 of 0.20 moldm-3 HClD 50 cm3 of 0.25 moldm-3 HCl

11. Which of the following is true? Catalyst ProcessA Iron Ostwald process for producing nitric acidB Vanadium(V) oxide Contact process for producing sulphuric acidC Platinum Haber process for producing ammoniaD Nickel Cracking process for producing alkane and alkene.

12. Which of the following has the highest rate of reaction?

13. Which of the following is incorrect about rate of reaction?

Reaction Time takenA Combustion of magnesium in oxygen 30 secondsB Photosynthesis 1 dayC Fermentation 2 daysD Rusting of iron 3 days

2

Time/s

A An increased in pressure decreases the rate of reaction.B The smaller the size of the solid particles, the higher the rate of reaction.C The higher the concentration of the reactant, the higher the rate of reaction.D The rate of reaction increases if the temperature of the reactants is increased.

14. Which of the following reactions will be affected by the changes in pressure?A 2H2O2 (aq) → 2H2O (l) + O2 (g)B N2 (g) + 3H2 (g) 2NH3 (g)C Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2 (g) D CaCO3 (s) + 2HCl (aq) CaCl2 + H2O (l) + CO2 (g)

15. Sulphur is precipitated when sodium thiosulphate solution is added with dilute hydrochloric acid in a conical flask. The rate of precipitation of sulphur can be increased byA using a bigger conical flask.B stirring the reaction mixture.C heating the reaction mixture.D adding water to increase the volume of mixture.

16. Why is food cut into small pieces before cookingA The food can be stirred easily.B The total pieces of food are more.C The total surface area of the food is larger.D The food can be cooked at a higher temperature.

17. The equation shows the reaction between calcium carbonate and dilute hydrochloric acid.CaCO3 + 2HCl → CaCl2 + CO2 + H2O

Based on the equation, which one of the following changes can be used to determine the rate of reactions in the above reaction?A Increase in the mass of calcium carbonate.B Increase in the concentration of hydrochloric acid.C Decrease in the concentrarion of calcium chloride.D Increase in the volume of carbon dioxide is produced.

18. The equation shows the reaction to produce hydrogen gas.H2SO4 + Zn → ZnSO4 + H2

Which of the following would increase the rate of production of hydrogen gas?A Increase the volume of acid.B Increase the size of zinc granules.C Increase the atmospheric pressure.D Increase the temperature of the mixture.

19. The graph shows the volume of carbon dioxide gas produced against time when calcium carbonate is added to dilute hydrochloric acid.

3

Volume of CO2/cm3

Which of the following statement explains the change in the gradient of the curve?A The temperature of the mixture decreases with time.B The concentration of hydrochloric acid decreases with time.C The total surface area of calcium carbonate increases with time.D The concentration of calcium chloride formed increases with time.

20. The graph shows the volume of carbon dioxide produced at room conditions when 1 g of calcium carbonate reacts with excess hydrochloric acid.

Calculate the overall rate of this reaction.A 6 cm3s-1

B 4 cm3s-1

C 3 cm3s-1

D 2 cm3s-1

21. The reaction between hydrochloric acid and zinc produces hydrogen gas. In an experiment, a maximum volume of 48.0 cm3 of hydrogen gas is produced in 120 s. What is the average rate of the reaction?A 0.2 cm3s-1

B 0.4 cm3s-1

C 1.8 cm3s-1

D 2.5 cm3s-1

22. The table shows the total volume of gas collected at regular intervals in a reaction.Time(s) 0 30 60 90 120 150 180 210Volume of gas(cm3) 0.0 4.0 7.4 10.4 12.8 14.6 17.2 17.2

What is the average rate of reaction in the second minute?A 0.080 cm3s-1

B 0.090 cm3s-1

C 0.107 cm3s-1

D 0.133 cm3s-1

23. Three experiments are conducted to compare the rate of a reaction. The results of the experiments are shown below:

Experiment Reactants Rate of reaction

I2 g of magnesium ribbon with 10 cm3 of 1.0 moldm-3 hydrochloric acid.

p

II 2 g of magnesium ribbon with 10 cm3 of 2.0 q

4

Time/s

Volume of CO2/cm3

moldm-3 hydrochloric acid.

III2 g of powdered magnesium with 10 cm3 of 2.0 moldm-3 hydrochloric acid.

r

Arrange the rate of reaction for the three experiments according to increasing order.A p, q, rB r, p, qC r, q, pD q, r, p

24. The table shows the results for two experiments.

Experiment ReactantsTime taken to collect

60 cm3 of H2(s)

11.0 g of magnesium ribbon and 50 cm3 of 1.0 moldm-3 sulphuric acid

30

21.0 g of magnesium powder and 50 cm3

of 1.0 moldm-3 sulphuric acid10

Based on the results, state the relationship between the sizes of solid particles with the rate of reaction.

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

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25. The graph shows the effect of adding copper(II) sulphate,CuSO4 solution to the reaction between zinc and hydrochloric acid. In this reaction, CuSO4 solution is used as a catalyst.

Based on the graph, state two characteristics of a catalyst.

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26. The figure shows the progress of a chemical reaction.Time(s) 0 5 10 15 20Progress of reaction particle of reactant. particle of product.

5

Vo

lum

e of

H2/c

m3

Time/s

With CuSO4 solution

Without CuSO4

solution

Based on the figure, describe what happens to the amount of reactant and the amount of product as the chemical reaction progresses.

……………………………………………………………...

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

..............................

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27. Which of the followings are the reasons for the use of catalysts in industrial processes?I. To reduce the cost of production. II. Enables the processes to be completed in a shorter time.III. Enables the processes to be carried out at a higher pressure.IV. Enables the processes to be carried out at a higher temperature.

A I and II only C II and III onlyB I and IV only D III and IV only

28. The use of a catalyst can increase the rate of a reaction, this is because A a catalyst reduces the activation energy.B a catalyst increases the activation energy.C a catalyst reduces the number of collision.D a catalyst increases the number of collision.

30 What is the gas produced when hydrogen peroxide decomposes?A Oxygen C Carbon dioxideB Hydrogen D Nitrogen dioxide

31 What is the function of manganese (IV) oxide?A To increase the volume of oxygen gas.B To decrease the volume of oxygen gas.C To change the chemical properties of hydrogen peroxide.D To increase the rate of decomposition of hydrogen peroxide

6

Catalysts are usually used to increase the rate of industrial processes. These enable the processes to be completed in a shorter time, at a lower temperature and pressure. Hence the cost of production will be reduced.

The presence of catalyst in a chemical reaction allows the reaction to take place through an alternative path which requires lower activation energy. Thus more colliding particles are able to achieve the lower activation energy. The frequency of effective collision increases and hence the rate of reaction is higher.

When a small amount of manganese (IV) oxide is added to hydrogen peroxide. Hydrogen peroxide decomposes rapidly to produce oxygen gas. Manganese (IV) oxide acts as a catalyst to increase the rate of decomposition of hydrogen peroxide.