Thermodynamics (Properties of Working Substance)

Question 1

study of heat and work and those properties of substances that bear a relation to heat and work.

Answer 1

Thermodynamics

Question 2

derived from Greek words theme, meaning “heat” an dynamics, meaning “strength” particularly applied to motion.

Answer 2

Thermodynamics

Question 3

a substance to which heat can be stored and from which heat can be extracted.

Answer 3

Working Substance

Question 4

a working substance whose chemical composition remains the same even if there is change in phase.

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Pure substance

Question 5

a working substance which remains in gaseous state during its operating cycle and whose equation of state is PV=mRT

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Ideal gas

Question 6

is the force per unit area. It may be described as a measure of the intensity force.

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Pressure

Question 7

pressure exerts by air as it has mass that is subjected to the action of the gravity.

Answer 7

Atmospheric Pressure

Question 8

are instruments used to measure the pressure of the atmosphere.

Answer 8

Barometers

Question 9

used to measure fluid pressure in a closed vessel.

Answer 9

Pressure gauges

Question 10

Pressure gauges commonly used in the refrigeration industry are

Answer 10

Manometer and bourdon tube

Question 11

type of gauge utilizes a column of liquid to measure the pressure, the height of the column indicating the magnitude of the pressure

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Manometer

Question 12

The liquid used in manometers is usually either

Answer 12

water or mercury

Question 13

is understood to be the “total” or “true” pressure of a fluid

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Absolute Pressure

Question 14

is the pressure as indicated by a gage

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Gage Pressure

Question 15

is the pressure measured relative to absolute vacuum., that, absolute zero pressure

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Absolute Pressure

Question 16

is a pressure that is less than atmospheric pressure. It is also a negative pressure.

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Vacuum Pressure

Question 17

is the pressure measured relative to atmospheric pressure.

Answer 17

Gage pressure

Question 18

a space that is devoid of matter, and in which the pressure is “zero”

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Perfect Vacuum

Question 19

is use to measure small and moderate pressure difference

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Manometer

Question 20

is commonly used mechanical pressure measurement device.

Answer 20

Bourdon Tube

Question 21

is the degree of hotness or coldness of a substance or body

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Temperature

Question 22

measure the level of the thermal pressure of a body

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Temperature

Question 23

the most frequently used instrument for measuring temperature is

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Thermometer

Question 24

measures the temperature of high-temperature gases

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Pyrometer

Question 25

Heat will pass from one body to another when and only ______ exists between the two bodies

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difference in temperature

Question 26

maybe defined as the mass divided by the volume or reciprocal of specific volume.

Answer 26

Density

Question 27

is the volume of a substance divided by its mass or reciprocal of density

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Specific Volume

Question 28

is the ratio of weight of an object to its volume.

Answer 28

Specific weight

Question 29

Is the ratio of the density of any substance to the density of water which is known as the standard density

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Specific Gravity

Question 30

heat energy due to the movement of molecules within the brought about its temperature

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Internal Energy

Question 31

Constant Specific heat process

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Internal Energy

Question 32

also called molecular energy

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Internal Energy

Question 33

What is the sum of all of the microscopic forms of energy called?

Answer 33

Internal Energy

Question 34

is the product of pressure and volume or specific volume

Answer 34

Flow Work

Question 35

is the sum of internal energy and flow work. It is also a function of temperature

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Enthalpy

Question 36

is a measure of molecular disorder, or molecular randomness. As a system becomes more disordered, the positions of the molecules become less predictable and it increases

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Entropy

Question 37

is an extensive property of a system

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Entropy

Question 38

Occurs when a solid turns to a liquid.

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Melting

Question 39

occurs when a liquid turns to a solid.

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Freezing or solidifying

Question 40

occurs when a liquid turns to a gas

Answer 40

Vaporization

Question 41

occurs when a gas (vapor) turns to a liquid

Answer 41

Condensation

Question 42

Occurs when a solid turns to a gas

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Sublimation

Question 43

is simply a change in the system state

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Process

Question 44

is the point in which solid, liquid and vapor occur

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Triple Point

Question 45

heat energy that causes or accompanies a change in the temperature of a substance is called

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Sensible heat

Question 46

Heat energy that causes or accompanies a change in the phase of a substance is known as

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Latent Heat

Question 47

When the change occurs between the solid and liquid phases in either direction, the latent heat involved is known as

Answer 47

latent heat of fusion.

Question 48

When the change occurs between the liquid and vapor phases in either direction, the latent heat involved is called

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Latent heat of vaporization