UNIVERSIDAD DE ANTIOQUIA FACULTAD DE INGENIERÍA

DEPARTAMENTO DE INGENIERÍA QUÍMICA

SITUATIONS TO ANALYZE - TERMODINÁMICA I – IQU 700 PROFESSOR: MAURICIO ESTEBAN SÁNCHEZ; SEMESTER 2011-1

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Problems analysis and Equations Of State (EOS)

Discuss and write any question you have about those situations in order to analyze it in the class

1. What pressure, a 0.16 m3 vessel should be filled with 42 kg of ethylene, in order to get a

temperature of 40°C?

2. A tank is filled with3 moles of n-pentane at 60 bar and 285°C. Determine the deviation

percentaje for volume calulation compare with an ideal gas for each of the equations: virial,

compressibility factor (2 and 3 parameters), Peng_Robinson, Soave Redlich Kwong and Patel-

Teja. Compare against Peng Robinson equation. What is the tank volume in liters?

3. What is an uncompressible substance.? Explain it in a phase diagram.

4. An open end mercurial manometer

shown below in the figure is connected

to a gas tank. The mercury meniscus in

the left leg of the manometer is

opposite 33.8 cm on the meter stick; in

the right leg it is opposite 16.2 cm.

Atmospheric pressure is 747 mm Hg.

Find the pressure of the gas.

5. A piston weighs 4.3 kg and has a cross sectional area of 450 mm2. Determine the pressure that

is exerted by this piston on the gas in the chamber. If the gas is water, what is it saturation

temperature?

6.

A pressure cooker has the lid screwed on tight.

A small opening with A = 0.0075 in2 is covered

with a petcock that can be lifted to let steam

escape. How much mass should the petcock

have to allow boiling at 250°F with an outside

atmosphere at 15 psia? If the cooker volume is

6L and is charged with 1.0 kg of water, ¿how

much water has to be evaporated?

7. En nuestro país se viene adelantando un programa de masificación de gas natural dentro del

cual se fomenta la conversión de los vehículos de gasolina a gas natural (GNV); para tal

propósito debe implementarse un nuevo tanque para almacenar el metano a alta presión. Si

se sabe que 140 ft3 de metano a 60°F y 1.0 atm de presión equivale a 1.0 galón de gasolina,

¿cual será el volumen del tanque requerido para almacenar un equivalente a 10 galones de

gasolina como gas natural a 3000 psia en Medellín?

UNIVERSIDAD DE ANTIOQUIA FACULTAD DE INGENIERÍA

DEPARTAMENTO DE INGENIERÍA QUÍMICA

SITUATIONS TO ANALYZE - TERMODINÁMICA I – IQU 700 PROFESSOR: MAURICIO ESTEBAN SÁNCHEZ; SEMESTER 2011-1

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8. A spherical helium balloon of 30 ft in diameter is at ambient T and P, 60 F and 14.69 psia.

How much helium does it contain? It can lift a total mass that equals the mass of

displaced atmospheric air. How much mass of the balloon fabric and cage can then be

lifted?

9. A substance is at 70°F and 300 lbf/in2 in a 10 ft3

tank. Estimate the mass from the

compressibility chart if the substance is a) air, b) butane or c) propane. Discuss.

10. Air in a car tires a -10°Cand 2 bar. After

the car is driven for some miles the

temperature rises to 12°C. What is the

new pressure?. Make your own

assumptions.

11.

A two-phase liquid–vapor mixture of H2O with an

initial quality of 25% is contained in a piston–cylinder

assembly as shown. The mass of the piston is 40 kg,

and its diameter is 10 cm. The atmospheric pressure

of the surroundings is 1 bar. The initial and final

positions of the piston are shown on the diagram. As

the water is heated, the pressure inside the cylinder

remains constant until the piston hits the stops. Heat

transfer to the water continues until its pressure is 3

bar. Friction between the piston and the cylinder wall

is negligible. Determine the total amount of heat

transfer, in J.

12. One kilogram of air, initially at 5 bar, 350 K, and 3

kg of carbon dioxide (CO2), initially at 2 bar, 450 K,

are confined to opposite sides of a rigid, well-

insulated container. The partition is free to move

and allows conduction from one gas to the other

without energy storage in the partition itself. The

air and carbon dioxide each behave as ideal gases.

Determine the final equilibrium temperature, in K,

and the final pressure, in bar, assuming constant

specific heats.