A 900 liter supply of xenon gas is held at 27 °C and 100 kPa. When the temperature is lowered to - 73

C, what pressure must be applied to compress the gas to 200 liters?

300 kPa

Explanation:

Concept tested: Gas Laws (Combined gas law)

Initial pressure, P₁ = 100 kPa

Initial temperature, T₁ = 27°C

But, K = °C + 273, therefore, T₁ = 300 K

Initial volume, V₁ = 900 L

New temperature, T₂ = - 73°C

= - 73°C + 273

= 200 K

New volume, V₂ = 200 L

We are required to calculate the new pressure, P₂

To find the new pressure of the gas, we are going to use the combined gas law; Combined gas law combines both Charles's law and Boyle's law. According to the combined gas law;

P₁V₁/T₁ = P₂V₂/T₂

To calculate the new Pressure, P₂, we rearranging the formula;

P₂ = (P₁V₁T₂) : (V₂T₁)

Therefore;

P₂ = (100 kPa * 900 L * 200 K) : (200 L * 300 K)

= 300 kPa

Therefore, a pressure of 300 kPa must be applied.