Answer:
It would take approximately
64.0
s
given those data.
Step-by-step explanation:
21.3
s
=
0.693
k
∴
k
≈
3.25
⋅
10
−
2
s
−
1
ln
(
1
8
)
=
−
3.25
⋅
10
−
2
s
−
1
⋅
t
∴
t
≈
64.0
s
Each equation I used is assuming this reaction's kinetics are of the first order, which is cited. The first equation is a simplified version for the half life of a first order reactant, and the second equation is the general equation for first order reactions in chemical kinetics.