Enthalpy Of Combustion

Since their discovery in 1985 , fullerenes have received the attention of many chemical researchers. In a recentrly reported data, the specific internal energy of combustion of crystalline C_(60) is found to be -36kJ g^(-1) at 298K . Compute the standard enthalpy of combustion and formation for the same. Standard enthalpy of combustion of graphite is -395kJ mol^(-1) . If the standard enthalpy of formation of diamond is +2kJ per mol of C- atom, which is more stable :C_(60) or diamond ?

If x_(1) , x_(2) and x_(3) are enthalpies of H-H , O=O and O-H bonds respective, and x_(4) is the enthaply of vaporisation of water, estimate the standard enthalpy opf combustion of bydrogen.

The enthalpy combustion of a substance

The enthalpies of combustion of carbon and carbon momoxide are -390KJ respectively. The enthalpy of fomation of CO in KJ is