Potassium chlorate, a common oxidizing agent in fireworks and matchheads, undergoes a solid-state disproportionation reaction when heated: 4KClO3 (s) 3KClO4 (s) + KCl (s). Use and S values to calculate (which is ) in kJ at 25C for this reaction. Enter a number with the correct sign to one decimal place, e.g. +123.4 or -123.4.