The heat of formation of liquid diatomic bromine is 0 kJ/mole. The heat of formation of gaseous diatomic bromine 30.9 kJ/mole. The heat of formation of gaseous monatomic bromine is 11.9 kJ/mole. What is the heat of the reaction which forms 1.00 mole of gaseous monatomic bromine from 0.500 mole gaseous diatomic bromine.