Thermodynamics Final

Question 1

System

Answer 1

A quantity of matter or a region in space chosen for study

Question 2

Surroundings

Answer 2

The mass or region outside the system

Question 3

Boundary

Answer 3

The real or imaginary surface that separates the system from its surroundings. Can be fixed or movable.

Question 4

Closed System (Control Mass)

Answer 4

A fixed amount of mass, and no mass can cross its boundary. Energy in the form of heat or work can cross. Volume doesn’t have to be fixed.

Question 5

Open System (Control Volume)

Answer 5

A properly selected region in space, both mass and energy can cross its boundary. Fixed volume.

Question 6

Control Surface

Answer 6

The boundaries of a control volume. It can be real or imaginary.

Question 7

Property

Answer 7

Any characteristics of a system such as P, T, V, and m.

Question 8

Intensive Properties

Answer 8

Those that are independent of the mass of a system, such as pressure, temperature, and density.

Question 9

Extensive Properties

Answer 9

Those whose values depend on the size - or extent - of the system.

Question 10

Specific Properties

Answer 10

Extensive properties per unit mass

Question 11

Specific Gravity

Answer 11

The ratio of the density of a substance to the density of some standard substance at a specified temperature (usually water at 4 degrees C) NO UNIT

Question 12

Specific Weight

Answer 12

The weight of a unit volume of a substance, HAS UNITS

Question 13

Equilibrium

Answer 13

A state of balance

Question 14

Thermal equilibrium

Answer 14

Same temperature throughout the entire system

Question 15

Mechanical Equilibrium

Answer 15

No change in pressure at any point of the system with time

Question 16

Phase Equilibrium

Answer 16

When the mass of each phase reaches an equilibrium level and stays there

Question 17

Chemical Equilibrium

Answer 17

No chemical reactions occur

Question 18

State Postulate

Answer 18

The state of a simple compressible system is completely specified by two independent, intensive properties.

Question 19

Process

Answer 19

Any change that a system undergoes from one equilibrium state to another

Question 20

Path

Answer 20

The series of states through which a system passes during a process

Question 21

Cv

Answer 21

Specific heat at constant volume

Question 22

Cp

Answer 22

Specific heat at constant pressure

Question 23

Kelvin Planck

Answer 23

It is impossible for any device that operates on a cycle to receive heat from a single reservoir and produce a net amount of work

Question 24

Clausius

Answer 24

It is impossible to construct a device that operates in a cycle and produces no effect other than the transfer of heat from a lower temperature body to a higher temperature body. A refrigerator cannot operate unless its compressor is driven by an external power source, such as an electric motor.