The bond energy of an O- H bond is 109 kcal mol 1. When a mole of water is formed from H and O atoms, then

(a) 218 kcal is released.

(b) 109 kcal is released.

(c) 218 kcal is absorbed.

(d) 109 kcal is absorbed.

choose and explain

It wil be A
two O-H bonds are there is H2O so 2*109 kcal
and energy is released in bond making 

Approved

218 kcal is released.

when forming 1mol of O-H bond 109kcal is released. Water has two O-H bonds. therefore (109 x 2)kcal is released.

Plz approve!

Approved

Dear Student,
Please find below the solution to your problem.

It will release 218 kcal.
Two O-H bonds are there is H2O so 2*109 kcal and energy is released in bond making.

Thanks and Regards