1. 已知 B2O3(s) + 3 H2O(g) → 3O2(g) + B2H6(g) ΔH = 2035 kJ/mol

            H2O(l) → H2O(g) ΔH = 44 kJ/mol

            H2(g) + (1/2) O2(g) → H2O(l) ΔH = -286 kJ/mol

            2 B(s) + (3/2) O2(g) → B2O3(s) ΔH = -1273 kJ/mol

試求出 2 B(s) + 3 H2(g) → B2H6(g) 的 ΔH 為多少 kJ/mol?