Question

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

• A. 104 K cal
• B. 10.4 K cal
• C. 1040 K cal
• D. 104.2 k cal

Answer 1

The correct option is A 104 K cal

Energy required for 4g hydrogen dissociation = $208kcal$
which means.
Energy required for 1 g hydrogen dissociation = $\frac{208}{4}=52kcal$

since, 1 mole of hydrogen = 2g
So, Energy required for 1 mole (2g) of hydrogen will be
= $52\times 2=104kcal$