Constant- volume calorimeter measures

At 298K in a constant volume calorimeter 0.01 mole of X was detonated when 8180 calories of heat was released DeltaU per mole of 'X'exploded is

Enthapy of combustion (Delta_(C ) H) depens on (i) whether combustion is carried out in constant volume calorimeter of constant pressure calorimeter (ii) the physical state of the substances (iii) the temperature at which combustion is carried out (iv) the amount of xygen present

In a constant volume calorimeter, 3.5 g of a gas with molecular weight 28 was burnt in ress oxygen at 298 K. The temperature of the calorimeter was found to Increase from 298 K to 298.45 K due to the combustion process. Given that the calorimeter constant is 2.5 KJ K^(-1) .Calculate the enthalpy of combustion of the gas in "kJ mol"^(-1) .