Given thatC+2S→CS2; ΔHf∘=+117.0kJ⋅mol−1       ....(1)C+O2→CO2; ΔHf∘=−393.0kJmol−1       .... (2)S+O2→SO2; ΔHf∘=−297.0kJmol−1          ...(3)The heat of combustion ofCS2+3O2→CO2+2SO2 is

The required combustion equation is obtained as2×eqn. (3)2S+2O2→2SO22×(−297.0)kJ+ eqn. (2)C+O2→CO2+(−393.0)kJ - eqn.(1)−C−2S→−CS2−(+117.0)kJor2S+3O2−2S→2SO2+CO2−CS2 or CS2+3O2→CO2+2SO2−1104kJmol−1