Answer
It takes $~~60.3~s~~$ for a mole of photons to be absorbed.
Work Step by Step
In part (b), we found that photons are absorbed at a rate of $~~9.98\times 10^{21}~photons/s$
We can find the time it takes for a mole of photons to be absorbed:
$t = \frac{6.02\times 10^{23}~photons}{9.98\times 10^{21}~photons/s} = 60.3~s$
It takes $~~60.3~s~~$ for a mole of photons to be absorbed.
