Question

The decomposition of NH₃ on a platinum surface is a zero-order reaction. If the rate constant (k)  is 4 x 10^-3 ms^-1, how long will it take to reduce the initial concentration of NH₃ from 0.1 M to 0.064 M?

Answer 1

Given that:
k = 4 x 10^-3 Ms^-1

`["A"_°]` = 0.1 M

[A] = 0.064 M
For a zero-order reaction,

k=`1/t {["A"_°]-["A"]}`

4 x 10^-3 Ms^-1 = `1/"t" {[0.1]-[0.064]}`

t =`( 0.1-0.064)/(4xx10^-3)=0.009xx10^3=9` seconds