A sample of Freon-12 (CF2CL2) occupies 25.5 L at 298 K and 153.3 kPa. Find it's volume at STP.

Data Given:

P₁ = 153.3 kPa

V₁ = 25.5 L

T₁ = 298 K

P₂ = 101.325 kPa

V₂ = ?

T₂ = 273 K

Solution:

Suppose the gas is acting Ideally, then According to Ideal Gas Equation,

P₁ V₁ / T₁ = P₂ V₂ / T₂

Solving for V₂,

V₂ = P₁ V₁ T₂ / T₁ P₂

Putting Values,

V₂ = (153.3 kPa * 25.5 L * 273 K) : (298 K * 101.325 kPa)

V₂ = 35.34 L

Result:

35.34 L volume is occupied at STP.