What is the volume of 0.750 moles of oxygen gas?

Question

What is the volume of 0.750 moles of oxygen gas at a temperature of 25C and a pressure of 99.0 kPa?

Answer 1

Use the formula for the Ideal Gas Law: PV = nRT

P = 99 kPa

T = 25^oC = 298 K

n = 0.750 moles

R = 0.0821 (atm⋅L) / (mol⋅K)

V = ????

We need to find V. Divide both sides by P to get:

V = nRT / P

We need to convert the units:

Celsius → Kelvin: K = C + 273 = 25 + 273 = 298

Kilopascals → Pascals → Atmospheres: 99 kPa = 99,000 Pa = 0.977 atm

V = (0.750 mol)(0.08201 atm⋅L/mol⋅K)(298 K) / (0.977 atm) = 18.8 L

The volume of 0.750 moles of oxygen gas is about 18.8 liters.