Since the heat of reaction ..is negative,.... it loses heat to.. the surroundings and therefore.. is exothermic. 2 NO(g) + O2(g) ---> 2 NO2(g) change in H= -114.1kJ molecular weight of NO2=80 so no of moles= 113.8/80=1.4225 so amount of heat produced =- 114.1/(2*1.14225) =40 kJ Solution Since the heat of reaction ..is negative,.... it loses heat to.. the surroundings and therefore.. is exothermic. 2 NO(g) + O2(g) ---> 2 NO2(g) change in H= -114.1kJ molecular weight of NO2=80 so no of moles= 113.8/80=1.4225 so amount of heat produced =- 114.1/(2*1.14225) =40 kJ.