JEE Main 2025 Chemistry question
Consider the following data : Heat of formation of CO2(g) = –393.5 kJ mol⁻¹ Heat of formation of H2O(l) = –286.0 kJ mol⁻¹ Heat of combustion of benzene = –3267.0 kJ mol⁻¹ The heat of formation of benzene is kJ mol⁻¹. (Nearest integer)
Answer: 48
Solution
ΔHc = 6ΔHf(CO2)+3ΔHf(H2O)–ΔHf(C6H6); –3267 = 6(–393.5)+3(–286)–ΔHf(C6H6); ΔHf(C6H6)=48 kJ/mol