Question

A first-order reaction has a half-life of 24 hours. What is its rate constant (k)?

• A. 0.0289 hr$^{-1}$
• B. 0.693 hr$^{-1}$
• C. 0.5 hr$^{-1}$
• D. 1.2 hr$^{-1}$

Hint:

For first-order kinetics, use \( k = \frac{0.693}{t_{1/2}} \) to find the rate constant from half-life.

Answer 1

The Correct Option is A

For a first-order reaction, the rate constant is calculated using the formula: \[ k = \frac{0.693}{t_{1/2}} = \frac{0.693}{24} = 0.0289 \, \text{hr}^{-1} \]