Answer
(a) $8.87\times10^{5}\,kJ/mol$
(b) $5.57\times10^{9}\,kJ/mol$
Work Step by Step
Recall: Energy of one photon= $\frac{hc}{\lambda}$
Energy of one mole of photons=
$\frac{hc}{\lambda}\times6.022\times10^{23}/mol$
(a) $E=\frac{(6.626\times10^{-34}\,J\cdot s)(3.00\times10^{8}\,m/s)}{0.135\times10^{-9}\,m}\times6.022\times10^{23}/mol$
$=8.87\times10^{5}\times10^{3}\,J/mol=8.87\times10^{5}\,kJ/mol$
(b) $E=\frac{(6.626\times10^{-34}\,J\cdot s)(3.00\times10^{8}\,m/s)}{2.15\times10^{-5}\times10^{-9}\,m}\times6.022\times10^{23}/mol$
$=5.57\times10^{12}\,J/mol=5.57\times10^{9}\,kJ/mol$