List of top Chemistry Questions on Chemical Kinetics asked in CUET (UG)

For a first-order reaction, the time required to reduce the concentration of the reactant to one-fourth of its initial value is 20 minutes. What is the half-life of the reaction?
The half-life of a first-order reaction is 25 minutes. Its rate constant is:
A drop of solution (Volume 0.05 mL) contains \( 3.0 \times 10^{-6} \) moles of H\(^+\) ions. If the rate constant of disappearance of H\(^+\) is \( 1.0 \times 10^{-7} \, \text{mol litre}^{-1} \text{sec}^{-1} \), how long will it take for H\(^+\) ions to disappear?
Ammonia is manufactured by:
\[ \text{N}_2(g) + 3\text{H}_2(g) \rightleftharpoons 2\text{NH}_3(g) \quad \Delta H_f^\circ = -46.1 \, \text{kJ/mol} \] The various steps involved are:
(A) Condensation of mixture of gases
(B) Passing the gaseous mixture over catalyst
(C) Compression of the mixture of gases
(D) Recirculation of the gaseous mixture
Choose the correct answer from the options given below: