When 0.485 g of compound X is burned completely in a bomb calorimeter containing 3000 g of water, a temperature rise of 0.285°C is observed. What is ΔU of the reaction for the combustion of compound X? The hardware component of the calorimeter has a heat capacity of 3.81 kJ/°C. The specific heat of water is 4.184 J/g.°C. The molar mass of compound X is 56.0 g/mol.
a) -4660 kJ/mol b) 4660 kJ/mol c) -538 kJ/mol d) 538 kJ/mol