Question

the bond dissociation energies of X2 Y2 and xy are in the ratio of 1:0.5:1delta H for the formation of xy is - 200kj the bond dissociation energies of X2 will be

Answer 1

Bond dissociation energy: The energy measure of a chemical bond A–B is defined as bond dissociation energy.

Energy is the enthalpy change when the bond A–B is separated by homolysis to give two fragments A and B.

Given:

Energy of x2 = 1

Energy of y2 = 0.5

Energy of xy = 1

ΔH for xy = -200KJ

Solution:

x2 + y2 -> 2xy

ΔH is given by Bond energy

So,

Bond energy (x-y) = a

Bond energy (x-x) = a

Bond energy (y-y) = a/2

ΔH f(x-y) = -200KJ

Therefore,

-400KJ for 2 moles

-400 = -a/2

a = 800KJ

Hence,  the bond dissociation energies of X2 will be 800 KJ per mole.