Heats of formation of SiO2 and MgO are -48.24 and -34.7 KJ respectively. The heat of the reaction: 2Mg+SiO2→2MgO+Si is
The heat of combustion for C, H2 and CH4 are −349 kJ/mol, −241.8 kJ/mol and −906.7 kJ/mol respectively. The heat of formation in kJ/mol of CH4 is :