The bond enthalpies of H2,X2 and HX are in the ratio of 2: 1: 2. If the enthalpy for formation of HX is −50kJmol−1 , the bond enthalpy of H2 is:
The bond enthalpies of H2,X2 an HX are in the ratio of 2 : 1 : 2. If enthalpy of formation of HX is −50 kJ mol−1, the bond enthalpy of X2 is