We have some gas in a container at high pressure. The volume of the container is
ID: 1705382 • Letter: W
Question
We have some gas in a container at high pressure. The volume of the container is 467 cm^3. The pressure of the gas is 2.52x10^5 Pa. We allow the gas to expand at constant temperature until its pressure is equal to the atmospheric pressure, which at the time is 0.857x10^5 Pa. (a) Find the work (J) done on the gas. (b) Find the change of internal engergy (J) of the gas. (c) Find the amount of heat (J) we added to the gas to keep it at constant temperature. Be sure to include the correct signs on the answers.Explanation / Answer
according to boyle's law , PV = constant P1V1 = P2V2 the final volume V2 = P1V1/P2 V2 = (2.52*10^5 Pa*467*10^-6 m^3)/0.857*10^5 Pa = 1373.20 *10^-6 m^3 (a) the work done on the gas is zero. the work, W= P(V2-V1) W = 2.52*10^5*906.20*10^-6 = 228.36 J (b) the change in internal energy, U = -228.36 J. (c) the amount of heat added to the gas to keep it at constant temperature is -228.36 J.