The dissociation energy of H2 is 430.53 kJ mol^-1. If hydrogen is dissociated by illumination with radiation of wavelength 253.7 nm, the fraction of the radiant energy which will be converted into kinetic energy is given by

Question

The dissociation energy of $\mathrm{H}_2$ is $430.53 \mathrm{~kJ} \mathrm{~mol}^{-1}$. If hydrogen is dissociated by illumination with radiation of wavelength $253.7 \mathrm{~nm}$, the fraction of the radiant energy which will be converted into kinetic energy is given by

(A) $100 \%$

(B) $8.78 \%$

(C) $2.22 \%$

(D) $1.22 \%$

Answer 1

Energy of 1 mole of photons,

$E=N_0 h v=\frac{N_0 \times h \times c}{\lambda}$

Energy converted into $K . E .=(472-430.53) \mathrm{kJ}$ $\%$ of energy converted into K.E.

$=\frac{(472-430.53)}{472} \times 100=8.78 \%$

So, The correct option of this question will be (B).