Question

The rate of a first order reaction is $1.5\times {10}^{-2}mol{L}^{-1}mi{n}^{-1}$ at 0.5 M concentration of the reactant. The half-life of the reaction is :

• A. 23.1 min
• B. 8.73 min
• C. 7.53 min
• D. 0.383 min

Answer 1

The correct option is A 23.1 min

Rate = k[C]
$k=\frac{\left[Rate\right]}{\left[C\right]}=\frac{1.5\times {10}^{-2}}{0.5}=3\times {10}^{-2}{t}_{\frac{1}{2}}=\frac{0.693}{3\times {10}^{-2}}=23.1min$