Chemistry - Ideal Gas Question with Solution | TestHub
A vertical cylinder closed from both ends is equipped with an easily moving piston dividing the volume into two parts, each containing one mole of air. In equilibrium at 320 K, the volume of the upper part is 4.0 times greater than that of the lower part. At what temperature (in kelvin) will the ratio of these volumes be equal to 3.0?
Answer:
Solution:
Equal moles and temperature on both sides, so Vu/Vl = Pl/Pu. Piston weight gives Pl = Pu + mg/S (constant difference).
At 320 K: Pl/Pu = 4 ⇒ mg/S = 3Pu. Total volume C: Vu = 4C/5, Vl = C/5, and Pu = R × 320/(4C/5) = 400R/C.
At T: ratio 3 ⇒ Pl' = 3Pu', and Pl' - Pu' = 2Pu' = mg/S = 3Pu ⇒ Pu' = 1.5Pu.
Also Pu' = RT'/(3C/4) = 4RT'/3C. So 4T'/(3C) = 1.5 × 400/C ⇒ 4T'/3 = 600 ⇒ T' = 450 K ⇒ 0450.
