Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

Chemical Kinetics

Long Answer Type

271. The reaction:

{CH}_{3} COF + H_{2} O \to {CH}_{3} COOH + HF

has been studied under the following initial conditions.

CASE I : CASE II : C_{H_{2} O} = 1.00 M C_{H_{2} O} = 0.02 M . C_{{CH}_{3} COF} = 0.01 M C_{{CH}_{3} COF} = 0.80 M

Concentrations were monitored as a function of time and are given below:

Determine the order of the reaction and the rate constant for the reaction.

132 Views

272.

For the hydrolysis of methyl acetate in aqueous solution, the following results were obtained:

t/s	0	30	60
[CH₃COOCH₃] / mol L^–1	0.60	0.30	0.15

(i) Show that it follows pseudo-first order reaction, as the concentration of water remains constant.

(ii) Calculate the average rate of reaction between the time intervals 30 to 60 seconds.

(Given log 2 = 0.3010, log 4 = 0.6021)

4347 Views

Short Answer Type

273.

For a reaction A + B → P, the rate is given by Rate = k[A] [B]²

(i) How is the rate of reaction affected if the concentration of B is doubled?

(ii) What is the overall order of reaction if A is present in large excess?

2667 Views

274.
A first order reaction takes 30 minutes for 50% completion. Calculate the time required for 90% completion of this reaction.

_{(log 2 = 0.3010)}

For the given first order reaction the rate constant for 50% completion is given by

Here t= time taken for 50% completion =30 min

[R]₀= initial concentration of the reactant

[R] =final concentration of the reactant

Let [R]₀be 100 and due to 50% completion of the reaction [R] will be 100-50 i.e. 50

Putting value in 1 we get

For same reaction the time required for 90% completion of the reaction can be computed using the expression

Here [R] = final concentration of reactant=100-90 =10

So we have

Therefore the time required for 90% completion of the given first order reaction is 100.13min.

3190 Views

275.

Write two differences between 'order of reaction' and 'molecularity of reaction?

1047 Views

276.

The following data were obtained during the first-order thermal decomposition of SO₂Cl₂ at a constant volume:

SO₂Cl₂(g)---> SO₂(g) + Cl₂(g)

Experiment	Time/s^-1	Total pressure/atm
1 2	0 100	0.4 0.7

Calculate the rate constant. (Given : log 4 = 0.6021, log 2 = 0.3010)

1000 Views

277.

A reaction is second order in A and first order in B.

(i) Write the differential rate equation.

(ii) How is the rate affected on increasing the concentration of A three times?

(iii) How is the rate affected when the concentrations of both A and B are doubled?

2371 Views

278.

A first order reaction takes 40 minutes for 30% decomposition. Calculate t_1/2 for this reaction.

(Given log 1.428 = 0.1548)

798 Views

279.

For a first order reaction, show that time required for 99% completion is twice the time required for the completion of 90% of reaction.

493 Views

Long Answer Type

280.

Rate constant ‘k’ of a reaction varies with temperature ‘T’ according to the equation:

where E_a is the activation energy.

When a graph is plotted for a straight line with a slope of -4250 K is obtained. Calculate ‘E_a’ for the reaction.

(R = 8.314 JK^-1 mol^-1)

1257 Views

Previous Year Papers

Test Series

Test Yourself

Long Answer Type

Short Answer Type

274. A first order reaction takes 30 minutes for 50% completion. Calculate the time required for 90% completion of this reaction. (log 2 = 0.3010)

Long Answer Type

274.
A first order reaction takes 30 minutes for 50% completion. Calculate the time required for 90% completion of this reaction.

_{(log 2 = 0.3010)}