Question

The electron affinity of chlorine is $3.7eV$. How much energy (nearest integer value) in $kcal$ is released when $2g$ of chlorine is completely converted to ${Cl}^{-}$ ion in a gaseous state? $(1eV=23.06kcal$ ${mol}^{-1})$

Answer 1

Given, $Cl+e⟶{Cl}^{-}+3.7eV$.

$\therefore$ Energy released for conversion of 2g gaseous chlorine into ${Cl}^{-}$ ions$=\frac{3.7\times 23.06\times 2}{35.5}=4.8kcal$ =5 kcal .

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