Chemical Kinetics MCQ Practice Test – NEET Chemistry (Free)

The unit of the rate constant of a second order reaction is

mol² L⁻² s⁻¹
mol L⁻¹ s⁻¹
s⁻¹
L mol⁻¹ s⁻¹

In a complex reaction, the overall rate is determined by the

fastest step
first step always
last step
slowest step

In collision theory, the probability (steric) factor P accounts for

the concentration
the temperature
the proper orientation of colliding molecules
the activation energy

A reaction for which the rate is independent of the concentration of the reactant is of

first order
second order
zero order
third order

Two reactions have activation energies of 40 kJ mol⁻¹ and 80 kJ mol⁻¹. For the same rise in temperature,

both increase by the same factor
the rate constant of the reaction with 40 kJ mol⁻¹ increases by a larger factor
the rate constant of the reaction with 80 kJ mol⁻¹ increases by a larger factor
neither changes

The half-life of a first order reaction is 5.0 × 10⁴ s. The percentage of the reactant remaining after 1.5 × 10⁵ s is

33.3%
25.0%
6.2%
12.5%

For a reaction with rate = k[A]², k = 0.5 L mol⁻¹ s⁻¹. The initial rate when [A] = 0.2 M is

0.01 mol L⁻¹ s⁻¹
0.04 mol L⁻¹ s⁻¹
0.1 mol L⁻¹ s⁻¹
0.02 mol L⁻¹ s⁻¹

For a reaction A → products, the rate becomes 8 times when [A] is doubled. The order of the reaction is

2
8
4
3

For a reaction 3A → 2B, the average rate of appearance of B is given by \( \dfrac{\Delta[B]}{\Delta t} \). The correct relation between the average rate of appearance of B and the average rate of disappearance of A is

\( \dfrac{-3\Delta[A]}{2\Delta t} \)
\( \dfrac{-2\Delta[A]}{3\Delta t} \)
\( \dfrac{\Delta[A]}{\Delta t} \)
\( \dfrac{-\Delta[A]}{\Delta t} \)

For the reaction A → 2B, if A disappears at 0.2 mol L⁻¹ s⁻¹, B is formed at

0.4 mol L⁻¹ s⁻¹
0.2 mol L⁻¹ s⁻¹
0.8 mol L⁻¹ s⁻¹
0.1 mol L⁻¹ s⁻¹

The rate of the reaction 2NO + Cl₂ → 2NOCl is given by the rate equation rate = k[NO]²[Cl₂]. The value of the rate constant can be increased by

increasing the temperature
increasing the concentration of NO
increasing the concentration of Cl₂
doing all of these

A positive catalyst increases the rate of a reaction. It also

increases the yield of products at equilibrium
changes the order of every reaction to zero
shortens the time needed to reach equilibrium
makes the reaction more exothermic

A catalyst does NOT change

the rate of reaction
the activation energy
the Gibbs energy change (ΔG) of the reaction
the path of the reaction

In the Arrhenius equation k = A e^−E_a/RT, A is called the

rate constant
frequency factor (pre-exponential factor)
activation energy
Boltzmann factor

The activation energy (E_a) and the rate constants (k₁ and k₂) of a chemical reaction at two different temperatures (T₁ and T₂) are related by

\( \ln\dfrac{k_2}{k_1} = -\dfrac{E_a}{R}\left(\dfrac{1}{T_1}-\dfrac{1}{T_2}\right) \)
\( \ln\dfrac{k_2}{k_1} = \dfrac{E_a}{R}\left(\dfrac{1}{T_2}-\dfrac{1}{T_1}\right) \)
\( \ln\dfrac{k_2}{k_1} = -\dfrac{E_a}{R}\left(\dfrac{1}{T_2}+\dfrac{1}{T_1}\right) \)
\( \ln\dfrac{k_2}{k_1} = -\dfrac{E_a}{R}\left(\dfrac{1}{T_2}-\dfrac{1}{T_1}\right) \)

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