Question

8) Energy required to dissociate 4g of gaseous hydrogen into free gaseous atoms is 208kcal at 25degCthe bond energy of H--H bond will be?

Answer 1

Dear student,
Given : heat of atomization of 4 g= 208kcal
$2H_2\to 4H∆H=208Kcal$
2g =1 mole
4gm =2 mole

Here 2 H-H bonds are broken by using 208 Kcal energy so in order to break 1 H-H bond we require

$\frac{208}{2}$=104 Kcal
Hence the bond energy of H-H bond will be 104 Kcal.
Regards!