Question

An automobile tire is inflated to a pressure of 3.05 atm on a rather warm day when the temperature is 40 C. The car is then driven to the mountains and parked overnight. The morning temperature is -5.0 C ( five below zero ). What will the pressure of the gas be in the tire at this temperature? Assume the volume of the tire doesn't change.

Answer 1

P1 = 3.05atm, T1 = 40C, T2 = -5.0C
T1 =273+40 =313K, T2=273K-5.0C = 268K
Use P1V1/T1 = P2V2/T2, but V1=V2 so they cancel each other out:
P1/T1 = P2/T2 --> P2 = P1T2/T1
P2 = (3.05)(268) / 313 = 2.61 atm