Question

One quantum is absorbed per gaseous molecule of Br${}_2$ for converting into Br atoms. If light absorbed has wavelength 5000 A, calculate energy required in KJ/mol.

Answer 1

$E=N_{o}hv$

$E=N_{o}hc/\lambda$

By putting all those values, we get-

$E=6.022\times {10}^{23}\times 6.626\times {10}^{-34}\times 3\times {10}^8/5000\times {10}^{-10}$

$=239.3$ KJ/mol