Question

Energy required to dissociate 4g of gaseous hydrogen into free gaseous atoms is 208 Kcal at ${25}^{o}C$. The bond energy of H - H bond will be:

• A. 1.04 Kcal
• B. 10.4 Kcal
• C. 104 Kcal
• D. 1040 Kcal

Answer 1

The correct option is C

104 Kcal

Energy needed to dissociate 4g is 208 Kcal

$\therefore$ Number of moles of $H_2$ = 2 mole
$\therefore$ Energy needed to dissociate 1 mole = $\frac{208}{2}$= 104 Kcal
$\therefore$ The bond energy is 104 Kcal in case of H - H bond.