TUISYEN IBNU SINA CHEMISTRY MODULE 12 RATE OF REACTION

1 The reaction between magnesium ribbon and hydrochloric acid can be shown as

Mg + 2HCl MgCl2 + H2.

The hydrogen gas evolved is collected in a burette. Volume of gas collected is recorded at intervals of 30 seconds. Table 1 shows the result obtained.Time (s) 0 30 60 90 120 150 180 210 240 270 300Volume of ( cm3) hydrogen

0 27 46 59 70 79 86 92 96 96 96

Table 1a i State 2 observations that can be seen in this experiment

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…………………………………………………………………………………………………..ii Suggest 2 ways to measure the rate of reaction according to the observation stated

above

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…………………………………………………………………………………………………..b Plot a graph of the volume of hydrogen gas collected against time

c Based on the graph plotted, determinei The average rate of reaction in the first 3 minutes

…………………………………………………………………………………………………..ii The average rate of reaction in the third minute

…………………………………………………………………………………………………..iii The overall average rate of reaction

…………………………………………………………………………………………………..iv The instantaneous rate of reaction at 1 minute

…………………………………………………………………………………………………..v The instantaneous rate of reaction at 3 minutes

…………………………………………………………………………………………………..d Compare the values of the instantaneous rate of reaction at 1 and 3 minutes

obtained in c (iv) and (v)

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TUISYEN IBNU SINA CHEMISTRY MODULE 12 RATE OF REACTION

2 A student carried out three experiments to study a factor that affects the rate of reaction. Diagram 1 shows the result for the experiment.

Experiment I II III

Set-up apparatus for

the experiments

Temperature / 0C

30 40 40

Time taken for all the

magnesium to dissolve/ s

50 20 15

a

Diagram 1

Write a chemical equation for the reaction between magnesium andnitric acid.

……………………………………………………………………………………………b i Name the gas produced in the experiment above.

……………………………………………………………………………………………ii Calculate the maximum volume of the gas produced in the experiment.

[Relative atomic mass : Mg,24;Volume of 1 mole of gas at room temperature = 24 dm3 ]

c i Calculate the average rate of reaction in cm3s-1 for:ii Experiment I

iii Experiment II

iv Experiment III

Excess nitric acid

Excess nitric acid

1.2g magnesium ribbon

1.2g magnesium ribbon

1.2g magnesium ribbon

Excess nitric acid

TUISYEN IBNU SINA CHEMISTRY MODULE 12 RATE OF REACTION