The interhalogen IFx can be made only by indirect routes. For example, xenon difluoride gas can react with iodine gas to produce IF_x and xenon gas. In one experiment, xenon difluoride is introduced into a rigid container until a pressure of 3.6 atm is reached. Iodine vapor is then introduced until the total pressure is 7.2 atm. Reaction is then allowed to proceed at constant temperature until completion by solidifying the IF_x as it is produced. The final pressure in the flask due to the xenon and excess iodine vapor is 6.0 atm.

(a) What is the formula of the interhalogen?

(b) Write the chemical equation for its formation.