Standard enthalpies of formation carbon dioxide, water and acetylene are -390, -286 and +254 kJ/molerespectively.Enthalpy of combustion of acetylene is equal to…..kJ/mole

Given,Cgraphite+O2g→CO2g,    ∆H=-390 kJ/mole....1 H2g+12O2g→H2O l,           ∆H=-286 kJ/mole....2 2Cgraphite+H2g→C2H2g, ∆H=+254 kJ/mole....3 Required equation is C2H2g+52O2g→2CO2g+H2Ol          2× Eq1+Eq2-Eq3=Required equation       2-390+-286-+254=Required equation                       -780-286-254=Required equation                                     ∆c0(C2H2)=-1320 kJ/mole