If, for a second-order reaction, the elapsed time after the first half-life is 338.871 seconds, the elapsed time after four half-lives would be (in minutes)...
t1/2= 1/k(A).
k= 1/t1/2*(A)=1/338.871 s(1)
(I let (A)=1).
k = ??
After 4 half lives, beginning of the 5th, (A) = 1/24 = 1/16 of the original.
then t1/2=[1/k(1/16)] =
16*1/k=16*338.871 = ??
Change to minutes.
Check my thinking.
So t1/2 =