Calculate the standard enthalpy of formation of acetylene (C₂H₂) using the information below.

2C (graphite) + H₂ (g) = C₂H₂ (g)
Given:
(a) C(graphite) + O₂(g) = CO₂ ∆H = -393.5 kJ/mol
(b) H₂ (g) + ½ O₂ (g) = H₂O (l) ∆H = -285.8 kJ/mol
(c) 2 C₂H₂ (g) + 5 O₂ (g) = 4 CO₂ (g) + 2H₂O (l) ∆H = -2598.8 kJ/mol