the heat of formation for carbon dioxide(g),water(g) and methane (g) are -400 kJ/mol ,-280kJ/mol and -70kJ/mol calc the heat of - Chemistry - Thermodynamics

Question

the heat of formation for carbon dioxide(g),water(g) and methane
(g) are -400 kJ/mol ,-280kJ/mol and -70kJ/mol calc the heat of
combustion of METHANE IN kJ/mol

Geetha · Accepted Answer

Heat of combustion of methaneCH4 + 2 O2 →CO2 + 2 H2O∆H = HP-HR           = 2 HCO2 + 2 HH2O  - HCH4 + 2HO2Enthalpy of formation of elements in elemental state = 0So∆H =  2 HCO2 + 2 HH2O  - HCH4      = (2 ×-400 + 2 × -280) - (-70)    = -800 -560 + 70      =- 1290 kJ/mol

the heat of formation for carbon dioxide(g),water(g) and methane (g) are -400 kJ/mol ,-280kJ/mol and -70kJ/mol.calc the heat of combustion of METHANE IN kJ/mol