could aomeone please show me step by step how to answer this

Use the AH, and AHrxn information provided: IF (g) + 12(5) IF (g) + 2 IF(8) AHrn = -89 kJ Compounds IF (g) IFs(8) AH (kJ/mol) -941 -840 a) Calculated AH, for IF. b) Calculate the mass of iodine solid used to produce 620 kJ of heat energy in the reaction. c) Sketch the energy profile for the above reaction and label the E, and AHrs on the graph