A tire is filled with air at 17 degreees C to a gauge pressure of 220 kPa. If the tire reaches a temperature of 39 degrees C, what fraction of the original air must be removed if the original pressure of 220 kPa is to be maintained? Please help step by step!

Answer 1

The absolute temperature increases by a ratio factor (273 +39)/(273+17) = 312/290 = 1.076

To keep BOTH the pressure and the tire volume the same, the number of moles must decrease by a factor 1/1.076 = 0.9295
The fraction of air than must be removed is 1 - 0.9295 = 7.1%