A 1.00-g sample of solid calcium was burned in fluorine to give a 1.95 g sample of pure CaF2. The energy given off in this reaction was 30.3 kJ. Given this information, we can say that the heat of formation of 1 mol of CaF2 is

Answer 1

Heat formation CaF2 is 30.3 kJ/1.95 g CaF2. Convert 1.95 g to moles if you want the answer in kJ/mol which is the usual way you find it in table.