Chapter 20, Problem 20.31E

The decomposition of ${\text{NH}}_3$:

$2{\text{NH}}_{\text{3}}\to {\text{N}}_{\text{2}}+3{\text{H}}_{\text{2}}$

is a zeroth-order reaction that, at elevated temperatures, has a rate constant of $1.04\times {10}^{-1}\text{M}/\text{s}$. If the initial concentration of ${\text{NH}}_3$ is $1.00\text{M}$, how long will it take for the concentration to drop to (a) $0.75\text{M}$; (b) $0.50\text{M}$; (c) $0.00\text{M}$?