The bond dissociation energy of X₂, Y₂ and X Y are in the ratio of 1: 0.5: 1 . H for the formation of X Y is -200 ~kJ / mol . The bond dissociation energy of X₂ will be

Step-by-step solution

Let the bond dissociation energy of X₂=a ~kJ / mol i.e. BE (X₂ )=a ~kJ / mol Then, BE ( Y ₂ )=0.5 a and BE (X Y)=a ~kJ / mol Given, 1 2 X₂+ 1 2 Y₂ X Y, H=-200 ~kJ / mol aligned _r H & = BE ( Rreactants )- BE ( Product ) _r H & = [ 1 2 BE (X₂ )+ 1 2 BE (Y₂ ) ]- BE (X Y) -200 & = a 2 + 0.5 a 2 -a a & = 200 0.25 =800 ~kJ / mol aligned