Question
If the bond dissociation energies of XY, X2 and Y2 (all diatomic molecules) are in the ratio of 1:1:0.5 and ∆f H for the formation of XY is -200 kJ mole-1. The bond dissociation energy of X2 will be
-
100 kJ mol-1
-
800 kJ mol-1
-
300 kJ mol-1
-
400 kJ mol-1
Solution
B.
800 kJ mol-1
XY→ X(g) + Y(g) ; ∆H +a kJ/ mole ............(i)
X2 → 2X; ∆H = +a kJ/mole........(ii)
Y2 → 2Y; ∆H =+0.5a kJ/mole.......(iii)
