First Order Reaction Kinetics

The reaction of hydrogen and iodine monochloride is given as:
H₂(g) + 2ICl(g) → 2HCl(g) + I₂(g)
This reaction is of first order with respect to H₂(g) and ICl(g), for which of the following proposed mechanisms:
Mechanism A:
H₂(g) + 2ICl(g) → 2HCl(g) + I₂(g)
Mechanism B:
H₂(g) + ICl(g) →HCl(g) + HI(g); slow
HI(g) + ICl(g) →HCl(g) + I₂(g); fast

1. B Only

2. A and B both

3. Neither A nor B

4. A only

In a first order reaction A B, if k is rate constant and initial concentration of the reactant A is 0.5 M then the half-life is :

(1)

(2)

(3)

(4)

If 60% of a first-order reaction was completed in 60 min, 50% of the same reaction would be completed in approximately:
(log 4 = 0.60, log 5 = 0.69)

Which of the following represents the factor by which the rate of a zero-order reaction increases when the temperature is raised from 10°C to 100°C, if the rate doubles for every 10°C rise in temperature?

1. 256 times

2. 512 times

3. 64 times

4. 128 times

A first-order reaction has a specific reaction rate of
10^–2 sec^–1. How much time will it take for 20 g of the reactant to reduce to 5 g?

If the rate constant for a first order reaction is k, the time (t) required for the completion of 99% of the reaction is given by:

1. t = 2.303/k

2. t = 0.693/k

3. t = 6.909/k

4. t = 4.606/k

For a first-order reaction A Products, initial concentration of A is 0.1 M, which becomes 0.001 M after 5 minutes. Rate constant for the reaction in min^-1 is