Ch 1 Rate of Reaction

RATE OF REACTION

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Ch 1 Rate of Reaction

1

The figure shows the graph of total volume of gas liberated against time for a reaction between marble and hydrochloric acid. It can be deduced from the graph thatA the rate of reaction at the 10th second is lower

than the rate of reaction a the 20th second.B the total volume of gas collected for the first

20 seconds is cm3

C the total volume of gas collected in the experiment is v cm3

D rate of gas production is maximum at the 40th second.

2 Which of the following acids will produce a

highest rate of reaction when 1 g of calcium carbonate is added to it?A 50.0 cm3 of 1.0 mol dm-3 nitric acidB 50.0 cm3 of 1.0 mol dm-3 sulphuric acidC 50.0 cm3 of 1.0 mol dm-3 ethanoic acidD 100 cm3 of 1.0 mol dm-3 hydrochloric acid

3

A flask containing calcium carbonate and dilute hydrochloric acid was placed on a top-pan balance. The mass was recorded every 10 seconds. When was the reaction slowest? A 0 secondsB 20 secondsC 40 secondsD 60 seconds

4

The graph shows the total volume of hydrogen gas liberated against time when a metal reacts with an acid in Experiment P and Experiment Q. Which of the following explains the difference between the two curves obtained in the experiments?

I The temperature of acid in Experiment P is higher than that in Experiment Q.

II A catalyst is used in Experiment P but not in Experiment Q.

III The number of moles of acid and metal used in Experiment P is more than that in Experiment Q

IV Metal powder is used in Experiment P but metal granules are used in Experiment Q

A III and IV onlyB I, II and III onlyC I, II and IV onlyD I, II, III and IV

5 Marble chips react with hydrochloric acid to form carbon dioxide gas. Which of the following explains why the rate of carbon dioxide produced decreases with time?

I The total surface area of the marble chips decrease with time

II The concentration of hydrochloric acid decreases with time

III Calcium chloride formed covers the surface of the marble chips

IV Heat energy is given off to the surroundingA I and II onlyB III and IV onlyC I, II and IV onlyD I, III and IV only

6 Which of the following, when mixed together, will liberate gas at the highest rate?A 5 g of limestone powder and 0.2 mol dm-3

hydrochloric acidB 5 g of limestone granules and 0.2 mol dm-3

hydrochloric acidC 10 g of limestone powder and 0.1 mol dm-3

hydrochloric acidD 10 g of limestone powder and 0.2 mol dm-3

hydrochloric acid7 5C2O4

2-(aq) + 16H+(aq) + 2MnO4-(aq)

→ 10CO2(g) + 8H2O(l) + 2Mn2+(aq)

Pn. Looi / 019-2379280

Time/s

0 10 20 30 40

Volume of gas /cm3

v

Time/s

Volume of hydrogen gas /cm3

Experiment P

Experiment Q

Time/s

Mass of flask and contents/g

׀ ׀ ׀ ׀ ׀ 70 60 50 40 30 20 0׀

100 –

-

50 -

-

In the above reaction between ethanadioic ion (C2O4

2-) and acidified potassium manganate(VII), excess acidified potassium manganate(VII) is used. The rate of reaction can be determined by measuringA the time for the Mn2+ ions to formB the time for the colour of MnO4

- to disappearC the mass of the manganate salt formed after a

certain timeD the time taken to collect a fixed volume of

carbon dioxide.

8 In a chemical reaction, a catalyst increases the rate of reaction byA decreasing the activation energy of the

reactionB increasing the energy of the particles of the

reactantsC reducing the frequency of effective collisionsD increasing the frequency of collision between

the particles of the reactants

9 The time taken for 5 g of marble chips to react completely with 50 cm3 of 2 mol dm-3 hydrochloric acid can be increased byA adding water to the reactantsB adding a catalystC replacing 5 g of marble chips with 5 g of

marble powderD adding concentrated hydrochloric acid to the

reactants

10 Magnesium ribbons of the same length are put into a few acid solutions . In which of the following acids will the magnesium ‘disappear’ fastest?A 100 cm3 of 2 mol dm-3 hydrochloric acidB 100 cm3 of 2 mol dm-3 etanoic acidC 100 cm3 of 1mol dm-3 nitric acidD 200 cm3 of 1 mol dm-3 hydrochloric acid

11

Gas X reacts with gas Y according to the following equation:

X(g) + Y(g) → Z(g)

Gas X and gas Y at room temperature, are put into the syringe as shown in the diagram. Which

of the following procedures will increase the rate of formation of Z? I Remove some of the mixture from the syringe II Put the syringe in water at room temperatureIII Pump in a small quantity of heliumIV Push the piston downwards

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

12 Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)

Zink powder was added to excess hydrochloric acid in an experiment. Which of the following graphs represent the change in the reactants and products with time?

I II

III IV

A I and III onlyB I, II and IV onlyC II, III and IV onlyD I, II, III and IV

13Experiment Reactants Initial rate

of reaction

I2 g magnesium ribbon and 10 cm3 0.5 mol dm-3

hydrochloric acidp

II2 g magnesium powder and 10 cm3 1.5 mol dm-3

hydrochloric acidq

III2 g magnesium powder and 10 cm3 1 mol dm-3 hydrochloric acid

r

The table shows three experiments carried out to study the initial rate of reaction of magnesium and hydrochloric acid.

piston

Mixture of gas X and gas Y

time

time

Concentration of hydrochloricacid

0

Concentration of hydrochloricacid

0

Concentration of zinc chloride

0

Volume of gas

0 time

time

3

Arrange in increasing order, the rate of reaction of the three experimentsA p, q, r C r, p, q B p, r, q D q, r, p

14

The curve P in the diagram shows the decomposition of 20 cm3 of 0.40 mol dm-3 hydrogen peroxide at 30oC, using 0.2 g of manganese(IV) oxide as a catalyst. Which of the following will result in the curve Q?

Exp

erim

ent

Vol

ume

of

hydr

ogen

pe

roxi

de

/ cm

3

Con

cent

rati

on o

f hy

drog

en

pero

xide

/ m

ol d

m-3

Qua

ntit

y of

m

anga

nese

(IV

) ox

ide

/ g

Tem

p-er

atur

e

/ o C

A

B

C

D

20

25

40

40

0.25

0.40

0.25

0.40

0.4

0.2

0.2

0.2

30

30

30

40

15 Which of the following are characteristics of a catalyst? I It changes the rate of a reaction II Its mass does not change after the reactionIII It increases the quantity of the productsIV Its effect on the rate of reaction depends on its

surface areaA I onlyB II and IV onlyC I, II and IV onlyD I, II, III and IV

16

ExptMass of copper(II)

Volume of hydrogen

Concentration of hydrogen

oxide/g

peroxide/cm3

peroxide/ mol dm-3

I 1 50 1.0II 1 100 0.5

Two experiments were carried out to measure the rate of decomposition of hydrogen peroxide, catalysed by copper(II) oxide. Which of the following graphs show the volume of oxygen liberated against time?

A C

B D

17 Nitrogen reacts with hydrogen to form ammonia according to the following equation:

N2(g) + 3H2(g) → 2NH3(g)

Which of the following graphs represents the change in the concentration of ammonia against time?

A C

B D

18

Time/s

Volume of oxygen /cm3

P

Q

Time

Concentration

Time

Concentration

Time

Concentration

Time

Concentration

Time / minute

Volume of oxygen / cm3

v

׀ t1

׀t2

Time

Volume

of gas

Experiment II

Experiment I

Time

Volume of gas

Experiment II

Experiment I

Time

Volume of gas

Experiment I

Experiment II

Time

Volume

of gas

Experiment I

Experiment II

4

The graph shows the volume of oxygen produced against time for the decomposition of sodium chlorate(I), NaClO.

2NaClO(aq) → 2NaCl(aq) + O2(g)

Which of the following can be deduced from the graph? I The average rate at which the gas is liberated

during the period t1 is cm3 minute-1.

II The rate of gas liberated is higher at the beginning of the experiment.

III The rate of gas liberated at t2 is zeroIV The rate of decomposition of sodium chlorate

decreases with time

A I, II and III onlyB I, III and IV onlyC II, III and IV onlyD I, II, III and IV

19 Hydrogen peroxide decomposes into oxygen and water as shown in the following equation.

2H2O2 → 2H2O + O2

Which of the following solutions containing hydrogen peroxide will decompose at the highest rate?

Concentration Temperature

A 0.05 mol dm-3 21oCB 0.05 mol dm-3 28oCC 0.02 mol dm-3 25oCD 0.02 mol dm-3 28oC

20 Which of the following pairs of substances will produce the highest initial rate of reaction?A 40 cm3 of 1 mol dm-3 HCl and 1 g marble

piecesB 20 cm3 of 2 mol dm-3 HCl and 1 g marble

powderC 40 cm3 of 3 mol dm-3 HCl and 1 g marble

powderD 40 cm3 of 2 mol dm-3 HCl and 1 g marble

powder

21 An increase in temperature will result in a higher rate of reaction because I the kinetic energy of the reactant particles

increases

II the activation energy of the reaction decreasesIII the frequency of effective collision increasesIV the energy required to break the chemical

bonding decreasesA I onlyB I and III onlyC II and III onlyD II and IV only

22

The graph shows the total volume of hydrogen gas liberated against time when magnesium reacts with excess sulfuric acid. Which of the following graph will be obtained if a little copper(II) sulphate is added?

A C

B D

23. Which of the following conditions will result in the highest rate of reaction when a fixed quantity of zinc is added to 100 cm3 of sulphuric acid?

Concentration of sulphuric

acid / mol dm-

3

Temperature/oC

Zink

ABCD

1.01.50.52.0

25203030

GranularGranularPowderedPowdered

24 Which of the following pairs are matched wrongly?

Industrial Process Catalyst

Time / s

Volume of hydrogen / cm3

40

׀30

Time / s

Time / s

Time / s

Volume of hydrogen / cm3

50 Volume of hydrogen / cm3

40

Time / s

Volume of hydrogen / cm3

40

Volume of hydrogen / cm3 25

׀30

׀40

׀20

׀30

5

A Contact Process Vanadium(V) oxideB Haber Process Iron filingC Ostwald Process NickelD Cracking of Petroleum Aluminium oxide

25 The function of a catalyst in a chemical reaction is toA increase the kinetic energy of the particles of

the reactantsB provide an alternative pathway with a lower

activation energyC promote collision between the particles of the

reactantsD absorb heat from the reactants

26 The initial rate of reaction between hydrochloric acid and 0.l mol dm-3 sodium thiosulphate solution can be increased ifA the volume of sodium thiosulphate solution is

increasedB 50 cm3 of water is added to the sodium

thiosulphate solutionC 0.2 mol dm-3 sodium thiosulphate solution is

used instead of 0.1 mol dm-3

D the temperature of acid hydrochloric solution is decreased

27 Which of the following properties of a catalyst will never change during a reaction?A appearanceB surface areaC physical stateD chemical composition

28 A chemical reaction between a solid and an acid is too fast for safe use by a class of students. Which set of changes is most likely to make the reaction safe for the students to use?

Piece of solid

Acid Temperature

A

B

C

D

Larger

Larger

Smaller

Smaller

Less concentratedMore concentratedLess concentratedMore concentrated

Lower

Higher

Lower

Higher

29 The graph shows how the total volume of hydrogen produced by a reaction between hydrochloric acid and excess magnesium varied with time.

Which statement about section XY of the curve is correct?A All the magnesium has reactedB No more hydrogen is being producedC The concentration of the acid is decreasingD The speed of reaction is at its maximum

30

Time / s 0 30 60 90 120 150 180 210

Volume of gas /cm3

0 2.0 3.7 5.2 6.4 7.3 8.6 8.6

The table shows the total volume of gas collected at regular intervals in a reaction. What is the average rate of reaction in the second minute?A 0.040 cm3s-1

B 0.045 cm3s-1

C 0.053 cm3s-1

D 0.062 cm3s-1

Chapter 1 Rate of reaction

Answers

Time

Total volume of hydrogen produced

X Y

6

1. C2. B3. D4. C5. A6. D7. D8. A9. A10. A11. D12. C13. B14. C15. C16. B17. D18. D19. B20. C21. B22. C23. D24. C25. B26. C27. D28. A29. B30. B

7