Question

What will be the minimum pressure required to compress 500 dm³ of air at 1 bar to 200 dm³ at 30°C? 

Answer 1

Volume of gas(V₁) = 500dm³   (given)

Pressure of gas (p₁) = 1 bar    (given)

Volume of compressed gas (V₂) = 200dm³  (given)

Now ,let P₂ be the pressure required to compress the gas.

Therefore at constant temperature P₁ V₁ = P₂ V₂(Boyle’s Law)

As a result P₂ = P₁ V₁ / V₂ = 1 X 500/200 = 2.5 bar

Therefore, the minimum pressure required is 2.5 bar.

Answer 2

Given, Initial pressure, 

p1 = 1 bar Initial volume, 

V1 = 500 dm3 Final volume, 

V2 = 200 dm3 Since the temperature remains constant, the final pressure (p2) can be calculated 

using Boyle’s law. 

According to Boyle’s law,