The half-life for a zero-order reaction having 0.02 M initial concentration of reactant is 100 s. The rate constant (in mol ${\mathrm{L}}^{-1} {\mathrm{s}}^{-1}$) for the reaction is

1. $1.0 \times {10}^{-4}$

2. $2.0 \times {10}^{-4}$

3. $2.0 \times {10}^{-3}$

4. $1.0 \times {10}^{-2}$

The temperature dependence of rate constant (k) of a chemical reaction is written in terms of Arrhenius equation, k = Ae^-Ea/RT . Activation energy E_a of the reaction can be calculated by plotting : 

(1) log vs 1 / log T

(2) k vs T

(3) k vs 1 / log T

(4) log k vs 1 / T

If the rate of the reaction is equal to the rate constant, the order of the reaction is : 

(1) 3

(2) 0

(3) 1

(4) 2

3A $\to$ B + C

It would be a zero order reaction when :

(1) The rate of reaction is proportional to square of concentration of A

(2) The rate of reaction remains same at any concentration of A

(3) The rate remains unchanged at any concentration of B and C

(4) The rate of reaction doubles if concentration of B is increased to double.

The activation energy for a simple chemical reaction A $\to$ B is E_a in forward direction. The activation energy for reverse reaction :

(1) Can be less than or more than E_a

(2) Is always double of E_a

(3) Is negative of E_a

(4) Is always less than E_a

For a chemical reaction $\mathrm{A}\to$ product, the postulated mechanism of the reaction is as follows.

$\mathrm{A}\underset{{\mathrm{k}}_2}{\overset{{\mathrm{k}}_1}{\rightleftharpoons }}3\mathrm{B}\underset{\mathrm{R}.\mathrm{D}.\mathrm{S}}{\overset{{\mathrm{k}}_3}{\to }}{\mathrm{C}}_{}$
If the rate constants for individual reactions are  k₁, k₂ and k₃, and activation energies are 
\(E_{a_{1}} = 180 \ kJ \ mol^{-1}, \)
\( E_{a_{2}} = 90 \ kJ \ mol^{-1}, \)
\( E_{a_{3}} = 40 \ kJ \ mol^{-1}\)
then overall activation energy for the reaction given above is

1. 70 kJ mol^-1

2. -10 kJ mol^-1

3. 310 kJ mol^-1

4. 130 kJ mol^-1

${}_{}$

1. Pseudo-first-order reaction

2. First-order reaction

3. Second order reaction

4. Third-order reaction

What is the rate equation for reaction 2A+ B $\stackrel{}{\to }$ C if the order of the reaction is zero ?

1.$k {\left[A\right]}^{0 }{\left[B\right]}^0$

2. $k {\left[A\right]}^1{\left[B\right]}^0$

3. $k {\left[A\right]}^1{\left[B\right]}^1$

4. None of these

For a certain reaction large fraction of molecules have energy more than the threshold energy, yet why the rate of reaction is very slow.It is due to improper: 

1. Orientation of colliding molecules.

2. Energy of colliding molecules.

3. Volume of colliding molecules.

4. Entropy of colliding molecules.

For a general reaction A $\to$ B, the plot of the concentration of A vs. time is given in the figure.
 

The slope of the curve will be: