# How do you determine the volume of gas in a container?

1. Apr 12, 2013

### Newbie12

1. The problem statement, all variables and given/known data

I have a container filled with argon and I need to find the volume and amount of gas in the container.

I don't know the mass or volume, but the measured pressure was 16.45psi, and the temperature was 298.59K.

2. Relevant equations

PV=nRT

P = pressure
V = Volume
n = amount of gas
R = Gas constant (8.3145 J/mol K)
T = temperature

P=ρRT/M

ρ=gas density (Argon: 1.784 g/L @ STP)
M=molar mass (Argon: 39.948 g/mol)

3. The attempt at a solution

I can figure out the density but not the volume or amount.

Does anyone have any thoughts for how to solve with equations or with an experiment?
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Apr 12, 2013

### phyzguy

If you only know the pressure and temperature, you can't figure out the total mass or volume. The gas could be a cubic centimeter or a cubic light year and have the same pressure and temperature.

3. Apr 12, 2013

### Curious3141

Can't you find the volume of the container - either by dimensions (if it's a simple geometric shape), or filling it with a liquid then measuring the volume decanted?

The gas will fill its container, so its volume will equal that of the container.

After that, you should be able to calculate the no. of moles (amount) using the ideal gas law you quoted.

BTW, how did you figure out the density of the gas in the container? Because the gas is not at STP.