# Easy Temperature and Kinetic Throey Problem

1. Nov 7, 2007

### spaumn

If 2.4m^3 of a gas initially at STP is compressed to 1.6m^3 and its temperature is raised to 30degreesC, what is the final pressure?

I thought this would be a easy one but my answers are coming out and dont look right.

I used pV=nRT

p=1.6m^3
V=2.4m^3
R=8.31J(mol*k) --- universal gas constant
T=30degreesC

So I plugged everything into the equation pV=nRT and solved for n and got .015403, it didnt look right so I converted 30degreesC to K (which equals 303.15K) then solved for n again and got .00154, which im sure is also wrong.

Am I using the wrong equation?? There was only a few to choose from in the book:

pV/T=Constant, pV=nRT, pV/T=NKsubB

2. Nov 7, 2007

### Midy1420

if you look at what you are given you have Po, Vo, To. Then we know it is compressed and the temp raises so we know T and V after. We have to solve for P. from the equations below theres one that uses those 3 variables.

3. Nov 7, 2007

### spaumn

Im assuming pV/T=constant, because the other two deal with molecules.

so p(2.4m^3)/30=1.6m^3?

4. Nov 7, 2007

### Midy1420

PV/T = constant (nK) and that works for both initial and final. Now you'll have two equations with two unknowns, Tfinal and constant

you also know initial pressure, initial volume, and initial temperature so you can find what the constant equals

Last edited: Nov 7, 2007