Question

What is the volume in L of a 0.825 mole sample of Ar at 600 mm Hg and 300 K?

Answer 1

Answer:

V = 25.7 L

Explanation:

To find the volume of Argon (Ar), you need to use the Ideal Gas Law equation. This looks like:

PV = nRT

In this formula,

        > P = pressure (atm)

        > V = volume (L)

        > n = number of moles

        > R = constant (0.0821 L*atm/K*mol)

        > T = temperature (K)

While there is a different constant that can be used if you want to keep the pressure in mmHg, there is a more common constant used when the pressure is in atm. So, to find the volume, you need to (1) convert mmHg to atm (by dividing by 760) and then (2) calculate the volume (using Ideal Gas Law).

(Step 1)

600 mm Hg              1 atm
-------------------  x  ---------------------  =  0.789 atm
                              760 mm Hg

(Step 2)

PV = nRT

(0.789 atm) x V = (0.825 mole)(0.0821 L*atm/K*mol)(300 K)

(0.789 atm) x V = 20.32

V = 25.7 L