A tank of gas consisting of 40% O₂ and 60% Ar and volume of 2 m³ is moved from storage at 20 $\circ$ C to the outside on a sunny day.Initially the pressure gauge reads 1200 psi After several hours the pressure reads 1600 psi.What is the new temperature of the gas in the tank?

Question

Quizplus · Accepted Answer

We can use the combined gas law which states that for a constant amount of gas, the pressure multiplied by the volume divided by the temperature is constant. Mathematically, 
P1V1/T1 = P2V2/T2 
where P1 = 1200 psi, V1 = 2 m3, T1 = (20 + 273) K (converted from 20°F to Kelvin), P2 = 1600 psi, and V2 = 2 m3.
We need to solve for T2, so we can rearrange the equation as:
T2 = P2V2T1 / (P1V1)
T2 = (1600 psi)(2 m3)(293 K) / (1200 psi)(2 m3) = 293 K which is equal to (293 - 273) = 20°C or 68°F
Therefore, the new temperature of the gas in the tank is 118°C or 244°F (Option D). Note that we converted the temperature from Kelvin to Celsius in the final answer.

A Tank of Gas Consisting of 40% O2 and 60 ∘\circ∘

A Tank of Gas Consisting of 40% O₂ and 60 $\circ$