MHT CET Chemistry Question (2026) — Solution

Step-by-step solution

The combustion reaction of carbon is given by: C(s) + O _2 (g) CO _2 (g) The heat of combustion of carbon to CO _2 is H = -393.5\ kJ/mol . Molar mass of CO _2 = 12 + 2 16 = 44\ g/mol . Number of moles in 35.2\ g of CO _2 is: n = 35.2 44 = 0.8\ mol The enthalpy change for the formation of 0.8\ mol of CO _2 is: H = 0.8\ mol (-393.5\ kJ/mol ) = -314.8\ kJ -315\ kJ The negative sign indicates that the heat is released during the process. Answer: -315\ kJ