Question

A first order reaction has a rate constant $k=3.01\times 10^{-3}/s$. How long it will take to decompose half of the reaction?

• A. 2.303 s
• B. 23.03 s
• C. 230.23 s
• D. 2303 s

Answer 1

Answer: (C)

$k=3.01\times 10^{-3}{s}^{-1}$
$t_{1/2}=?$
$k=\frac{0.693}{t_{1/2}}$ (for a first order reaction)
$\therefore t_{1/2}=\frac{0.693}{k}=\frac{0.693}{3.01\times 10^{-3}}$