Question

4. The decomposition of N20s in the gas phase is first order in N20s. If the concentration of N2Os drops from

0.200 M to 0.100 M in 14.2 minutes, how long would it take for N2Os to drop from 0.200 M to 0.025 M?

Answer 1

42.5 mins

Step-by-step explanation:

Given that for a first order reaction;

ln[A] = ln[A]o - kt

[A] = 0.1 M

[A]o = 0.2 M

t= 14.2 mins

ln0.1 = ln0.2 - 14.2t

ln0.1 - ln0.2/-14.2=k

k= -2.303 -(-1.609)/-14.2

k= 0.0489 min-1

So;

ln0.025 =ln0.2 - 0.0489t

ln0.025 - ln0.2/-0.0489 =t

t= -3.689 - (-1.609)/-0.0489

t= 42.5 mins