A reaction $2 A P$ is second order in $A$ . It is 30% complete in $20 min$ . Calculate the time (in minutes, two decimals) required, from the start, for the reaction to be 80% complete.

Numerical answer type, answer in min, tolerance 0.05.

Answer: 186.67 min

For second order, fraction reacted

f

obeys

k [A]_{0} t = f / (1 - f)

. From the first data point

k [A]_{0} = (0.30/0.70) /20 = 0.02143 mi n^{- 1}

. For

f = 0.80

f / (1 - f) = 4.00

, so

t = 4.00/0.02143 = 186.67 min