An ideal gas in a sealed container has an initial volume of 2.55 l. at constant pressure, it is cooled to 18.00 °c where its final volume is 1.75 l. what was the initial temperature?

Data Given:

V₁ = 2.55 L

T₁ = ?

V₂ = 1.75 L

T₂ = 18 °C + 273.15 = 291.15 K

Solution:

Let suppose the Gas is acting Ideally, Then According to Charle's Law,

P₁ / T₁ = P₂ / T₂

Solving for T₁,

T₁ = V₁ * T₂ / V₂

Putting Values,

T₁ = (2.55 L * 291.15 K) : 1.75 L

T₁ = 424.24 K

Or,

T₁ = 151 °C