Question

Which of the following does not represents bond dissociation energy of one mole bonds :-
1. H2(g) → 2H(g)
2. Cl2(g) → 2Cl(g)
3. H2O(g) → 2H(g) + O(g)
4. O2(g) → 2O(g)​

Answer 1

The following does not represent the bond dissociation energy of one mole bonds:-

3. H2O(g) → 2H(g) + O(g)

- H2 has a single bond so its dissociation represents the dissociation of one mole of bonds.

- Cl2 also has a single bond, hence its dissociation represents the dissociation of one mole of bonds.

- In H2O, there are 2 -OH bonds. Hence, its dissociation does not represent the dissociation of one mole of bonds.

- The dissociation of oxygen molecules also represents the dissociation of one mole of bonds.