Question

For first order reaction, the rate constant for the decomposition of \(\text{N}_{2}\text{O}_{5}\) is \(6\times 10^{-4}\) s\({}^{-1}\). Calculate half life period for decomposition in terms of seconds

• A. \(1100\)
• B. \(1225\)
• C. \(1155\)
• D. \(1050\)

Hint:

For a first-order reaction, half-life equals 0.693 divided by the rate constant.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
For a first-order reaction, \(t_{1/2} = \dfrac{0.693}{k}\), independent of concentration.

Step 2: Substitute
\(k = 6\times 10^{-4}\text{ s}^{-1}\), so \(t_{1/2} = \dfrac{0.693}{6\times 10^{-4}}\).

Step 3: Result
\(t_{1/2} = 1155\) s.

Final Answer:
The half-life is 1155 seconds. \[ \boxed{\text{(C) }1155} \]