You propose two reaction mechanisms for a reaction you are studying. You

experimentally determine that the overall reaction is lst order with respect to

$(C{H}_3{)}_{3}CBr$ and $0$ th order with respect to cyanide. Which mechanism$($s$)$ is$/$are valid?

Explain your answer.

Mechanism A

Step $1$: $(C{H}_3{)}_{3}CBr(C{H}_3{)}_3{C}^{+}+B{r}^{-}$

Step $2$: $(C{H}_3{)}_3{C}^{+}+C{N}^{-}(C{H}_3{)}_{3}CCN$

Overall: $(C{H}_3{)}_{3}CBr+C{N}^{-}(C{H}_3{)}_{3}CCN+B{r}^{-}$

Mechanism B

Single$-$step: $(C{H}_3{)}_{3}CBr+C{N}^{-}(C{H}_3{)}_{3}CCN+B{r}^{-}$