1 Thermodynamics (30.0 Points)

A cylindric tank contains a cryogenic, binary mixture of nitrogen (index 1) and oxygen

(index 2). The tank has a diameter of d = 1.23 m and a height of h = 2.1 m. Due to process

data available to you, you know the mass of nitrogen M₁ = 5.84 kg and the mass of oxygen

M₂ = 13.68 kg inside the tank. The temperature of the mixture is T = -155.2 °C.

Given:

.

M; in kg

kmol

Nitrogen

28.01

Oxygen 32.00

Tki in K Pki in bar

126.2

33.9

154.6

50.5

A₁

B₁

Ci

0.040 6.99100 308.365 273.200

0.021 7.11477 370.757 273.200

وليا

Binary parameter for nitrogen/oxygen k12 = -0.0104

Universal gas constant R = 8314 kmol K

Antoine equation with the parameters A₁, B₁, C₁

log10 Pai = A₁ -

B₁

T+C₁

with T in °C, Psi in mbar

Tasks:

First, you want to know the state your mixture is in. For that purpose, you calculate the

pressure p using an equation of state.

1.) Calculate the mole fraction y₁ of nitrogen and the mole fraction y2 of oxygen in the

mixture and finally the molar volume of the mixture. (7.0 Points)