an ideal gas in a sealed container has an initial volume of 2.65 L. at constant pressure, it is cooled to 18.00 degrees C where its final volume is 1.75 L.

Question

what was the initial temperature?

Answer 1

Constant pressure is an example of Charles' Law where V₁/T₁ = V₂/T₂

(2.65 L)/(T₁) = (1.75 L)/(291 K)

T1 = ((2.65 L)(291 K)/1.75 L) = 440 K 

440K - 273 = 168ºC

 

 

Answer 2

At constant pressure,

 

T₁/V₁ = T₂/V₂ ⇒

 

T₁ = (V₁/V₂)T₂ = [(2.65 L)/(1.75 L)] [(18.00 + 273.15)K] = 440.88 K = 167.73°C