Question

What is the half life period of the first order reaction whose rate constant is \(2.31 \times 10^{- 1} \mathrm{~s}^{- 1}\)

• A. \(3 \times 10^{11} \mathrm{~s}\)
• B. \(3 \times 10^{12} \mathrm{~s}\)
• C. \(6.3 \times 10^{-13} \mathrm{~s}\)
• D. \(4 \times 10^{-13} \mathrm{~s}\)
• E. \(3 \times 10^{-13} \mathrm{~s}\)

Hint:

Half-life for first order is independent of initial concentration. \(t_{1/2} = \ln 2 / k\).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
For first order reaction, half-life \(t_{1/2} = \frac{0.693}{k}\).

Step 2: Detailed Explanation:
Given \(k = 2.31 \times 10^{-12} \text{ s}^{-1}\).
\(t_{1/2} = \frac{0.693}{2.31 \times 10^{-12}} = 3 \times 10^{11} \text{ s}\).

Step 3: Final Answer:
The half-life is \(3 \times 10^{11}\) seconds.