The decomposition of dimethylether at 504℃ is first order with a half-life of 1570. seconds. What fraction of an initial amount of dimethylether remains after 4710. seconds?

a. 1/6

b. 1/8

c. 1/32

d. 1/16

e. 1/3

1/8

Explanation:

From;

Nt/No = (1/2) ^t/t1/2

N = amount of dimethylether present at time t

No = amount of diethylether present at time t=0

t = time taken for N molecules of diethylether to remain = 4710 seconds

t1/2 = half-life of diethylether = 1570 seconds

Substituting values;

Nt/No = (1/2) ^4710/1570

Nt/No = (1/2) ^3

Nt/No = 1/8

Hence after 4710 seconds only 1/8 molecules of dimethylether will remain