If the bond dissociation energies of X Y, X₂ and Y₂ (all diatomic molecules) are in the ratio of 1:1:0.5 and _t H for the formation of X Y is -200 ~kJ ~mole ⁻¹ . The bond dissociation energy of X ₂ will be

Step-by-step solution

aligned & X Y X_ (g) +Y_ (g) ; H =+ a kJ / mole . .( i ) & X ₂ 2 X ; H =+ a kJ / mole (ii) & Y ₂ 2 Y ; H =+0.5 a kJ / mole . (iii) & 1 2 . (ii) + 1 2 (iii) - . (i), Gives & 1 2 X ₂+ 1 2 Y ₂ XY ; H = (+ a 2 + 0.5 2 a - a ) kJ / mole & + a 2 + 0.5 a 2 - a =-200 & a =800 . aligned