# One quantum is absorbed per molecule of gaseous iodine for converting into iodine atoms.If light absorbed has wavelength of $5000A^{\large\circ}$,calculate energy required in KJ/mol.

$\begin{array}{1 1}(a)\;146.3KJ/mol&(b)\;369.4KJ/mol\\(c)\;296.4KJ/mol&(d)\;239.3KJ/mol\end{array}$

$E=N_0hV=\large\frac{N_0hc}{\lambda}$
$\Rightarrow \large\frac{6.02\times 10^{23}\times 6.626\times 10^{-34}\times 3\times 10^8}{5000\times 10^{-10}}$
$\Rightarrow 239.3\times 10^3J/mol$
$\Rightarrow 239.3\times KJ/mol$
Hence (d) is the correct answer.