Gaseous iodine pentafluoride, IF₅, can be prepared by the reaction of solid iodine and gaseous fluorine:

I₂(s) + 5F₂(g) → 2IF₅(g)

A 10.00 L flask is charged with 21.0 grams of I₂ and 2.00 atm of F₂ at 25 °C. The flask is heated to 100 °C until one of the reagents is completely consumed. What will be the percentage of IF₅ (by mole) in the final product mixture? (Assume ideal gas behavior).