Given the standard enthalpy changes for the following two reactions: (1) 2C (9) + 2H-(g)—С,Н. (g)ДН 3D 52.3 kJ (2) 2C(s) + 3H,(g) C,H,(g)AH° = -84.7 kJ what is the

standard enthalpy change for the reaction: (3) C,H,(g) + H2(g) C,H(g)ΔΗ%3D