In certain first order reactions the concentration of the reactant decreases from 0.15 M to 0.11 M in 36 minutes . calculate the time of half reactions
ln(No/N) = kt
No = 0.15
N = 0.11
t = 36 min
Solve for k
Then k = 0.693/t1/2
You know k from above, solve for t1/2