The rate constant of a radioactive substance is $4$ ${\mathrm{years}}^{-1}$. The value of half-life will be : 

1. 0.05 years

2. 0.17 years

3. 0.26 ${\mathrm{years}}^{-1}$

4. 1.6 years

The rate constant for a first-order reaction is $4.606\times {10}^{-3}$ $s^{-1}$. The time required to reduce 2.0 g of the reactant to 0.2 g will be:

The graph that represents a first-order reaction is:

1.		2.
3.		4.

The half-life period for a first-order reaction is 20 minutes. The time required to change the concentration of the reactants from 0.08 M to 0.01 M will be:

The half-life of ⁹²U₂₃₈ against \(\alpha\)-decay is 4.5 × 10⁹ year.  The time taken in a year for the decay of the 15/16 part of this isotope will be:

1. $9.0\times {10}^9$

2. $1.8\times {10}^{10}$

3. $4.5\times {10}^9$

4. $2.7\times {10}^{10}$

The rate constant of a first-order reaction is\(4 \times 10^{-3} \mathrm{sec}^{-1}.\) At a reactant concentration of \(0.02~\mathrm{M},\) the rate of reaction would be:

The half-life time for the decomposition of a substance dissolved in ${\mathrm{CCl}}_4$ is 2.5 hours at $\mathrm{30 }°$C. The amount of substance that will be left after 10 hours if the initial weight of the substance is 160 gm is:

For a reaction of the type 2A + B $\to$ 2C, the rate of the reaction is given by $k{\left[A\right]}^2\left[B\right]$. When the volume of the reaction vessel is reduced to $\frac{1}{4}$ th of the original volume, the rate of reaction changes by a factor of -

1. 0.25                                                          

2. 16

3. 64                                                             

4. 4

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

If ‘a’ is the initial concentration of a substance which reacts according to zero-order kinetics and k is the rate constant, the time for the reaction to go to completion will be: