The rate law of a reaction is rate = k[D][X]. What are the units of the rate constant?

Mar 13, 2017

The rate constant $k$ takes on whatever units it needs to such that the units on the lefthand side are the same as on the righthand side. Supposing the units on the left are $\text{M/s}$, we really just have:

"M"/"s" = (???)("M")("M")

Solve for the ???.

"M"/"s" xx 1/("M" cdot "M") = ???

Thus,

??? = color(blue)(1/("M"cdot"s"))

or

$\textcolor{b l u e}{{\text{M"^(-1)cdot"s}}^{- 1}}$

or

color(blue)("L"/("mol"cdot"s"))