The heat of combustion of ethylene at 18∘C and at constant volume is -335.8 K cal when water is obtained in liquid state. What is the heat of combustion at constant pressure and at 18∘C.
The heat liberated on complete combustion of 7.8g benzene is 327 KJ. This heat has been measured at constant volume and at 270 C. What is the heat of combustion of benzene at constant pressure at 270 C (R = 8.3 J mol−1 K−1)