Question

Explain first-order reaction. The value of velocity (rate) constant \( k \) for a first-order reaction is \( 5 \times 10^{-14} \, \text{s}^{-1} \). Calculate the half-life period of the reaction.

Hint:

The half-life of a first-order reaction is independent of the initial concentration of the reactant.

Answer 1

- First-order Reaction: The rate of reaction depends on the concentration of a single reactant. The rate law is: \[ \text{Rate} = k[A]. \] - Half-life (\( t_{1/2} \)): For a first-order reaction: \[ t_{1/2} = \frac{0.693}{k}. \] Calculation: \[ t_{1/2} = \frac{0.693}{5.5 \times 10^{-14}} = 1.26 \times 10^{13} \, \text{s}. \]