Given the standard enthalpy changes for the following two reactions:
4 C(s) + 5 H2(g)  C4H10(g) ΔHo = -125.6 kJ
C2H2(g)  2 C(s) + H2(g) ΔHo = 226.7 kJ
What is the standard enthalpy change for the reaction:
2 C2H2(g) + 3 H2(g)  C4H10(g) ΔHo = ?