Question

Determine the energy of $1$ mole photons of radiations whose frequency is $5\times {10}^{10}{s}^{-1}$. $(h=6.62\times {10}^{-34}J-s)$.

Answer 1

Energy of $1$ photon=$hv=(6.62\times {10}^{-34}\times 5\times {10}^{10}{s}^{-1})J$

$1$mole contains $6.023\times {10}^{23}$ photons=$N_A$ (Avogadro's number)

Energy of $1$mole photons=$hv\times N_A=33.13\times {10}^{-24}\times 6.023\times {10}^{23}=200\times {10}^{-1}J/mole=20J/mole$