Find the quantity that increases when the concentration of reactants in a reaction is increased.

1.	Heat of reaction	2.	Threshold energy
3.	Collision frequency	4.	Activation energy

Which of the following is the time required to reduce the amount of a reactant from 2.0 g to 0.2 g for a first-order reaction with rate constant \(k = 4.606 \times 10^{-3} \, \text{s}^{-1}\)?

The half-life for a zero-order reaction having 0.02 M initial concentration of reactant is 100 s. The rate constant (in mol L^–1 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. $1.0\times {10}^{-2}$

What does Z_AB represent in the collision theory of chemical reactions?

For a reaction, the activation energy is zero, and the rate constant at 200 K is 1.6 × 10⁶ s⁻¹.
Find the rate constant at 400 K.

Given: R = 8.314 J K⁻¹ mol⁻¹.

A first-order reaction has a rate constant of 2.303 × 10¯³ s¯¹. The time required for 40 g of this reactant to reduce to 10 g will be
[Given that ${\log }_{10}2=0.3010$]

For a reaction A$\to$B, enthalpy of reaction is $-4.2$ $\mathrm{kJ}\hspace{0.17em}{\mathrm{mol}}^{-1}$ and enthalpy of activation is $9.6$ $\mathrm{kJ}\hspace{0.17em}{\mathrm{mol}}^{-1}$. The correct potential energy profile for the reaction is:

1.		2.
3.		4.

The slope of Arrhenius Plot (ln k v/s $\frac{1}{\mathrm{T}}$) of the first-order reaction is $-5\times {10}^3$ $\mathrm{K}$. The value of E_a of the reaction is:

[Given R = 8.314 JK^–1 mol^–1]

For the chemical reaction ${\mathrm{N}}_2\left(\mathrm{(g)}\right)+3{\mathrm{H}}_2\left(\mathrm{(g}\right)$ )$\rightleftharpoons$ $2{\mathrm{NH}}_3\left(\mathrm{(g)}\right)$ the correct option is:

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