Question

Energy of one mole of photons of radiation whose frequency is $ 5\times 10^{14}\,Hz $ is

• A. $ 199.51\,kJ\,mol^{-1} $
• B. $ 189.51\,kJ\,mol^{-1} $
• C. $ 198.51\,kJ\,mol^{-1} $
• D. $ 188.51\,kJ\,mol^{-1} $

Answer 1

Answer: (A)

$\because$ Energy of $1$ photon, $R=h v$
$\therefore $ Energy of $1$ mole of photon,
$E'=N_{A} h v$
$=6.022 \times 10^{23} \times 6.626 \times 10^{-34} \times 5 \times 10^{14}$
$=199.508 \times 10^{3} J\,mol ^{-1}$