Q17 / 150 · MHT CET 2022 (07 Aug Shift 1) · Chemistry

What is the time required for completion of $90 \%$ of a first order reaction?

  • Correct answer
    A
    $\frac{2.303}{k}$
  • B
    $\frac{0.3010}{\mathrm{k}}$
  • C
    $\frac{0.693}{2 \mathrm{k}}$
  • D
    $\frac{2 \times 0.693}{k}$

Solution

$\begin{aligned} & \mathrm{t}=\frac{2.303}{\mathrm{k}} \log \frac{\mathrm{a}_0}{\mathrm{a}_{\mathrm{t}}} \\ & \mathrm{t}=\frac{2.303}{\mathrm{k}} \log \frac{100}{10} \\ & \mathrm{t}=\frac{2.303}{\mathrm{k}}\end{aligned}$

Hence, the correct answer is option: 'A'.

Relevant Questions