250 cm3 of 0.50 mol.dm 3 sodium hydroxide solution and 250 cm3 of 0.50 mol.dm3 hydrochloric acid were mixed in a calorimeter. All three were at the same temperature. The rise in temperature was 5.OK. Caldulate the standard enthalpy of neutralisation. Assume no heat passes to the container Specific heat (c) of water is 4.2 J K1 g