# What are the units of the rate constant, k, for the decomposition of H_2O_2(aq)?

May 29, 2017

Well, we must know by experiment that the process

$2 \text{H"_2"O"_2(aq) -> "O"_2(g) + 2"H"_2"O} \left(l\right)$

is a first order process... hence, the units follow. Write the rate law, giving the initial rate of reaction as a function of the rate constant $k$ and concentration $\left[\text{ }\right]$.

$r \left(t\right) = k \left[{\text{H"_2"O}}_{2}\right]$

$\text{M"/"s" = [???]cdot"M}$

$\implies k$ is in $\boldsymbol{{\text{s}}^{- 1}}$.