How Do I Solve for Final Pressure in an Ideal Gas Problem?

[dnl65078]

Please Help! Kinetic Energy Problem

1. The initial pressure in an ideal gas is 1.40 atm when its temperature is 299 K. The temperature is increased to 315 K and the volume is increased to 1.29 times its initial value. Calculate the final pressure.

2. R = 8.31 J/molK

PLEASE HELP!

THANKS IN ADVANCE!

 

[ideasrule]

What have you tried already?

 

[dnl65078]

Thats just the thing. I cannot figure out what formula to use. The formula's I have are PV=nRT and PV=NKbT... none of the formulas I was given seem to be valid for a "change in temp/volume"

 

[ideasrule]

Try writing out PV=nRT for both the "before" and "after" situations. You'll be able to solve for the final pressure from there, even though you don't know n (and don't need to know R).

 

[VesperJazz]

Make 2 equations and solve by dividing the equations. Cancel out the same unknown.