JEE Main 2020 Chemistry question
The heat of combustion of ethanol into carbon dioxides and water is –327 kcal at constant pressure. The heat evolved (in cal) at constant volume and 27°C (if all gases behave ideally) is (R = 2 cal )
Answer: -326400
Solution
ΔU = ΔH − Δ = −327000 + 2(300) = −326400 cal; the key is given as −326400.