Question

The rate constant of the reaction
$2H_2{O}_2\left(aq\right)\to 2H_{2}O\left(l\right)+O_2\left(g\right)$ is $3\times {10}^{-3}mi{n}^{-1}$. At what concentration of $H_2{O}_2$, the rate of the reaction will be $2\times {10}^{-4}M{s}^{-1}$?

• A. $6.67\times {10}^{-3}M$
• B. 2 M
• C. 4 M
• D. 0.08 M

Answer 1

The correct option is C 4 M

$-\frac{d\left[H_2{O}_2\right]}{dt}=k[H_2{O}_2{]}^1$

$\therefore 2\times {10}^{-4}=\frac{3\times {10}^{-3}}{60}\times \left[H_2{O}_2\right]$

Or $\left[H_2{O}_2\right]=4M$