The half-life period of a first order chemical reaction is 6.93 minutes. The time required for the completion of 99% of the chemical reaction will be (log 2 = 0.301):

1. 23.03 minutes

2. 46.06 minutes

3. 460.6 minutes

4. 230.3 minutes

Identify the correct statement for a zero-order reaction.

1. A reaction in which reactants do not react

2. A reaction in which one reactant is present in large excess

3. A reaction whose rate remains constant with time

4. A reaction whose rate increases with time

For A + B $\to \hspace{0.17em}$C + D, $∆$H = -20 kJ mol^-1 , the activation energy of the forward reaction is 85 kJ mol^-1. The activation energy for the backward reaction is…. kJ mol^-1.

For the elementary reaction M $\to$ N, the rate of disappearance of M increases by a factor of 8 upon doubling the concentration of M. The order of the reaction with respect to M will be:

1. 4

2. 3

3. 2

4. 1

The rate constant for a second order reaction is 8x10^-5 M^-1 min^-1 . How long will it take a 1M solution to be reduced to 0.5M?

1. 8.665 x 10³ minute

2. 8 x 10^-5 minute

3. 1.25 x 10⁴ minute

4. 4x10^-5 minute

The time for half-life of a first order reaction is 1 hr. What is the time taken for 87.5% completion of the reaction?

1. 1 hour

2. 2 hour

3. 3 hour

4. 4 hour

Which order of reaction obeys the relation t_1/2 = 1/Ka?

1. First

2. Second

3. Third

4. Zero

Find the correct rate law for the decomposition of ozone:

2O₃ → 3O₂

Mechanism:

O₃ ⇌ O₂ + O (Fast equilibrium)
O + O₃ → 2O₂ (Slow)

1. r = k[O₃]²
2. r = k[O₃]²[O₂]⁻¹
3. r = k[O₃][O₂]
4. Rate law cannot be predicted

The rate of reaction becomes 2 times for every 10°C rise in temperature. How the rate of reaction will increase when temperature is increased from 30°C to 80°C?

1. 16

2. 32

3. 64

4. 128

What fraction of a reactant showing first order remains after 40 minute if t_1/2 is 20 minute?

1. 1/4

2. 1/2

3. 1/8

4. 1/6