# Homework Help: Need help on a Chem Question

1. Oct 16, 2006

### PhysicsNoob88

Question: A sample of hydrogen gas, collected at 100 C and 1.0 atm., has a volume of 350 ml (0.350 lit.). What will be the pressure after it is transferred to a 4.0 lit. flask and cooled to 25 C? (temp must be in degrees of Kelvin)

I had assumed using the formula V2 = P1 X V1 / P2 but i am not getting anything that makes sense. I think its two formulas needed but am not sure. Any assistance would be greatly apperciated

2. Oct 16, 2006

### Smith4046

Go to your favorite search engine and type in "combined gas law".

Think that will help.

Best of health.

Steve

3. Oct 16, 2006

$$pV = nRT$$. Look at the values given. Which ones are being kept constant?

4. Oct 16, 2006

### PhysicsNoob88

Thanks! That did the trick alright

5. Oct 16, 2006

### PhysicsNoob88

Can someone verify this is correct?

P1V1/T1 = P2V2/T2
(1.0atm)(.35lit)/(373K) = P(4.0lit)/(298K)
(104.3) = (1492)P
.070atm = P

6. Oct 16, 2006