Question

The half-life of a substance in a first-order reaction is $15$ minutes. The rate constant is

• A. $2.46 \times 10^{2} \min ^{-1}$
• B. $4.62 \times 10^{-2} \min ^{-1}$
• C. $3 \times 10^{-5} \min ^{-1}$
• D. $3 \times 10^{-9} \min ^{-1}$

Answer 1

Answer: (B)

$k =\frac{0.693}{ t _{1 / 2}}=\frac{0.693}{15}$
$=4.62 \times 10^{-2} \min ^{-1}$