Amass of gas has a volume of 4 m3, a temperature of 290 k, and an absolute pressure of 475 kpa. when the gas is allowed to expand to 6.5 m3, its new temperature is 277 k. what's the absolute pressure of the gas after expansion?

We are going to use the ideal gas law. First, convert 475 kPa to Pa because the ideal gas law uses SI units. This will be 475,000 Pa. 
Rearranging the ideal gas law, we get P1V1/T1 = P2V2/T2. Now plug everything in and solve for P2: (475,000)(4)/(290) = (P2)(6.5)/(277)

Answer evaporation and condensation;