At a pressure of 10 ^ 5 Pa and a temperature of 15 degrees Celsius, the air has a volume of 2 liters.

At a pressure of 10 ^ 5 Pa and a temperature of 15 degrees Celsius, the air has a volume of 2 liters. At what pressure will air of a given mass take a volume of 4 liters if its temperature becomes equal to 20 degrees Celsius?

Data: P1 (initial air pressure) = 105 Pa; T1 (initial temperature) = 15 ºС (absolute temperature T1 = 288 K); V1 (original volume) = 2 l; V2 (volume that the air will take) = 4 liters; T2 (end temperature) = 20 ° C (absolute temperature T2 = 293 K).
We express the required air pressure from the proportion: P1 * V1 / T1 = P2 * V2 / T2, whence P2 = P1 * V1 * T2 / (T1 * V2).
Calculation: P2 = 10 ^ 5 * 2 * 293 / (288 * 4) = 0.509 * 10 ^ 5 Pa.
Answer: The air must be under a pressure of 0.509 * 10 ^ 5 Pa.