Question

physical chemistry helium compression question

4) (12 points) Helium is compressed isothermally and reversibly at 100°C from a pressure (per mole). w (per mole), Δ of 2 bar to 10 bar. Calculate q (per mole),w/per mole). Δ 6A.AH, a, and as. 4, Δ-AU, and Δ-

Answer 1

Answer:

T = 100C = 373K

P₁ = 2 atm, P₂ = 10 atm

W =2.303RT logP₁/P₂

R = 8.314 JK^-1mol^-1

W = 2.303 x 8.314 x 373 log 2/10

W = 7141.88 log 0.2

W = 7141.88 (-0.6989)

W = - 4991.46 J

Negative value indicates the work done on the system.

In Isothermal comdition $\Delta$ H =0

In Isothermal process the Entropy change

$\Delta$ S = 2.303R log P₁/P₂

$\Delta$ S = 2.303 x 8.314 x log 2/10

$\Delta$ S = 19.147 x (-0.6989)

$\Delta$ S = - 13.3819

The negative value of Entropy means the Entropy (disorderness) decreases.

$\Delta$ G = $\Delta$ A

$\Delta$ G = $\Delta$ H - T $\Delta$ S

$\Delta$ G = 0 - 373 ( - 13.3819)

$\Delta$ G = 4991.4 J

$\Delta$ G value is the positive value, That indicates Nonspontaneous.