Question

The unit of rate of a first order reaction is:

• A. $molli{t}^{-1}$
• B. $lmo{l}^{-1}{s}^{-1}$
• C. $s^{-1}$
• D. $l^{2}mo{l}^{-2}{s}^{-1}$

Answer 1

The correct option is C $s^{-1}$

For a first order reaction; rate law can be wriiten as; $r=k[A{]}^1$
Therefore k = $\frac{r}{\left[A\right]}=\frac{mol\times l^{-1}\times s^{-1}}{mol\times l^{-1}}$ = $s^{-1}$ where concentration of $A=$ moles per litre and rate of reaction; r = change in concentration of $A$ with time.