521.

The activation energy for a reaction at the 37. temperature T K was found to be 2.303 RT J mo1^-1. The ratio of the rate constant to Arrhenius factor is

• 10^-1

• 10^-2

• 2 × 10^-3

• 2 × 10^-2

Time required for 100 per cent completion of a zero order reaction is

• 2k/a

• a/2k

• a/k

• ak

The time required for 100% completion of a zero order reaction is

• ak

• $\frac{\mathrm{a}}{2\mathrm{k}}$

• $\frac{\mathrm{a}}{\mathrm{k}}$

• $\frac{2\mathrm{k}}{\mathrm{a}}$

The following data is obtained during the first order thermal decomposition of 2A(g)→ B(g) +C(s) at constant volume and temperature.

S.No	Time	Total pressure in Pascal
1.	At the end of 10 min	300
2.	After completion	200

The rate constant in min^-1

• 0.0693

• 6.93

• 0.00693

• 69.3

For a reaction, A + B → products, the rate of the reaction at various concentrations are given below

Expt no.	[A]	[B]	Rate (mol dm-3 s-1)
1.	0.2	0.2	2
2.	0.2	0.4	4
3.	0.6	0.4	36

The rate law for the above reaction is

• r = k[A][B]²

• r = k [A]³[B]

• r = k [A]²[B]²

• r = k [A]²[B]

The rate of reaction increases with rise in temperature because of

• onl increase in number of activated molecules

• Increase in energy of activation

• decrease in energy of activation , increase in number activated molecules and also the number of effective collisions increase.

• only increase in the number of effective collisions

A first order reaction is 60% complete in 20 minutes. How long will the reaction take to be 84% complete?

• 68 min

• 40 min

• 76 min

• 54 min

If 50% of the reactant is converted into a product in a first order reaction in 25min, how much of it would react in 100min?

• 93.75%

• 87.5%

• 75%

• 100%

Temperature coefficient of a reaction is 2. When temperature is increased from 30°C to 90°C, the rate of reaction is increased by

• 60 times

• 64 times

• 150 times

• 400 times

A (g) $\stackrel{∆}{\to }$ P (g) + Q (g) + R (g), follows first order kinetics with a half-life of 69.3 s at 500°C. Starting from the gas 'A' enclosed in a container at 500°C and at a pressure of 0.4 atm, the total pressure of the system after 230 s will be

• 1.15 atm

• 1.32 atm

• 1.22 atm

• 1.12 atm