The evaporation of a 120-nm film of n-pentane from a single crystal of aluminum oxide is zero order with a rate constant of
\(1.92*10^{13} \frac{molecules?}{cm^{2}*s}\)
at 120K.

a. If the initial surface coverage is 8.9*10^16 molecules/cm^2, how long will it take for one-half of the film to evaporate?

b. What fraction of the film is left after 10 s? Assume the same initial coverage as in part a.