Question

The bond dissociation energies of x2 y2 and xy are in the ratio of 1:0.5:1 delta h for the formation of xy is -200 kjmol^-1 the bond dissociation of x2 will be

Answer 1

The energy required for the dissociation of a bond between two atoms is known to be bond dissociation energy whereas, the energy required for the fomration of a bond between the atoms is known to be bond formation energy.

The bond formation energy is equivalent to bond dissociation energy such as for XY, the bond formation energy is -200 kJ /mol which gets equivalent to bond dissociation energy. So, bond dissociation energy will be + 200 kJ /mol, the + sign indicates the energy is consumed for breaking the bond.

Now, the ratio of of bond dissociation energy of X_2 :Y_2 :XY is 1 : 0.5 : 1. The bond dissociation energy of X_2 and XY is equal as + 200 kJ /mol.