# Homework Help: Pressure problem from chem

1. Nov 3, 2009

### LeonJHardman

1. The problem statement, all variables and given/known data
A bicycle tire is filled with air to a pressure of 68 psi, at a temperature of 28°C. Riding the bike on asphalt on a hot day increases the temperature of the tire to 58°C. The volume of the tire increases by 3.9%. What is the new pressure in the bicycle tire?

2. Relevant equations
PV=NRT

3. The attempt at a solution
Well... I went through it first by changing psi into pascals, then Celcius into Kelvin. then I made an attempt to find volume which I got 5.9736e-4 for. ( i kind of ignored the moles because I ddidn't know what to do with it, so I put it in as 1 to pretty much negate it) then I multiplied the volume by 1.039 and plugged in the R constant and 359.15 K to try to find pascals. which I got 47484.6921 Pascals, but it asked for answers in psi, so I tried to switch it to psi by dividing by 6894.8 and got 6.89 psi. I don't think this is even close to right.

2. Nov 3, 2009

### symbolipoint

Your main quantities are P, V, T. The quantities of n and R are not needed. Neither of these last two would change. Do you remember how P, V, and T by themselves are related?

3. Nov 3, 2009

PV= T right?