Ideal gas law combined gas law

Question

A 3.20 L container holds 0.200 mols of oxygen gas at 325 K. What is the pressure inside the container?

Answer 1

Use the Ideal Gas Law

PV = nRT

P = pressure in atmospheres

V = volume in liters = 3.2 L

n = moles = 0.200 moles

R = gas law = 0.0821 Latm/Kmol

T = temperature in Kelvin = 325K

Solve for P:

P = nRT/V = (0.200)(0.0821)(325) / 3.2 L

P = 1.67 atm (3 sig. figs.)

Answer 2

Hi Pia B,

Thank you for your excellent question. In order to solve this problem, we will be using the Combined Gas Law Equation:

We will need to plug in our known values and solve for Pressure (P).

Our known values are:

Volume= 3.20L

n= 0.200 mols

Temperature= 325 K

R= 8.314

Now, let's solve for Pressure (P):

P * (3.20L) = (0.200)(8.314)(325K)

Once solved, you should receive a pressure of 168.87 once plugged into the calculator. You will next need to convert to the units your teacher/professor recommends.

It should be 168,878kPa for the overall Pressure within the container.

I hope this helps!