ExB(g) + B2(g) → ExB3(g) Use the following chemical equations and their respective enthalpy changes to calculate AHn for the formation of ExB, in kJ/mol. 2 ExB(g) + A2(g) → Ex2A(g) + B2A(g) DeltaН = 170. 2 ExB3(g) + 2 A2(g) →Ex2A(g) + 3 B2A(g) Delta H= 340. 2 B2(g) + A2(g) → 2 B2A(8) Delta H=-43.4