question_answer 1)

  If the combustion of 1 g of graphite produces 20.7 kJ of heat, what will be the molar enthalpy change? Give the significance of sign also.

Answer:

  Heat of combustion \[\Delta H\] = - Heat released by 1 mole or 12 g of carbon \[=-20.7\times 12\] \[=-248.4kJ\,mo{{l}^{-1}}\]