Given the information below calculate ?H°rxn for: C2H4(g) + 6F2(g) => 2CF4 + 4HF(g) --------------------------------------------------------------- H2(g) + F2(g) => 2HF(g) ?H° = -537 kJ C(s) + 2F2(g) => CF4(g) ?°H = -680 kJ 2C(s) + 2H2(g) => C2H4(g) ?H° = 52.3 kJ answer is -2486 kJ. could you show your work for this? its very confusing