Question

The rate constant of the reaction
$2H_{2}O_{2} \, \left(a q\right) \, \rightarrow \, 2H_{2}O \, \left(l\right)+ \, O_{2} \, \left(g\right)is \, 3 \, \times \left(10\right)^{- 3}\left(m i n\right)^{- 1}$
At what concentration of $H_{2}O_{2} \, ,$ the rate of the reaction will be $2 \, \times \, 10^{- 4} \, Ms^{- 1}$ ?

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

Answer 1

Answer: (C)

$-\frac{d \left[H_{2} O_{2}\right]}{d t}=k\left[H_{2} O_{2}\right]^{1}$
$\therefore \, \, 2\times 10^{- 4}=\frac{3 \times 10^{- 3}}{60}\times \left[H_{2} O_{2}\right]$
$or \, \, \left[H_{2} O_{2}\right]=4 \, M$