Question
A sample consisting of 1.00 mol Ar is expanded isothermally at 0°C
from 22.4 dm3 to 44.8 dm3 (a) reversibly, (b) against a constant external
pressure equal to the final pressure of the gas, and (c) freely (against zero
external pressure). For the three processes calculate q, w, ΔU, and ΔH.
from 22.4 dm3 to 44.8 dm3 (a) reversibly, (b) against a constant external
pressure equal to the final pressure of the gas, and (c) freely (against zero
external pressure). For the three processes calculate q, w, ΔU, and ΔH.
Answers
S
(Ans. (a) ∆U = ∆H = 0; q = 1.57KJ, w = −1.57KJ, (b) ∆U =
∆H = 0; q = 1.13KJ, w = −1.13KJ, (c) ∆U = ∆H = 0; q = 0, w =
0.)
∆H = 0; q = 1.13KJ, w = −1.13KJ, (c) ∆U = ∆H = 0; q = 0, w =
0.)
Shikha bharti
à) w=-1.57kj, ∆u=0(as isothermal process) and Q= ∆u-w=0-(-1.57kj) =1.57kj
b) w=-1.134kj ,∆u =0and q=1.134kj
c) w=0(as pext. =0) so p*∆v=0=w
∆u=0and q=0
b) w=-1.134kj ,∆u =0and q=1.134kj
c) w=0(as pext. =0) so p*∆v=0=w
∆u=0and q=0