THERMO Lesson P= C, T = C, V = C

Question 1

_______ are substances that have UNIFORM and CONSISTENT chemical composition and retain their distinct properties regardless of the conditions or phases it may undergo.

Answer 1

Pure Substances

Question 2

Pure substances can exist in different phases, such as solid, liquid, or gas, depending on the ______ and _______ conditions.

Answer 2

Temperature and Pressure

Question 3

____________ is the state at which solid, liquid and gas coexist

Answer 3

Triple point

Question 4

The 3D P-V-T surface model provides a visual representation of how pressure, volume, and
temperature influence the behavior of a substance. It is also known as the ________.

Answer 4

Phase Diagram.
Phase Space Diagram

Question 5

__________ is where the saturated liquid and saturated vapor lines meet

Answer 5

Critical Point

Question 6

For Water, the triple point is at t = _______ and P = __________

Answer 6

t = 0.01degree C and P = 0.611657 kPa

Question 7

For water, the Critical Point is at t = ________ and P = _________

Answer 7

t = 374.13 degreeC and P = 22,090 kPa

Question 8

The __________________ is given by the Pressure – Specific Volume, PV projection

Answer 8

The Ice-Water-Water Vapor System

Question 9

The _______________ is given by the Pressure – Temperature, PT projection

Answer 9

Phase Diagram

Question 10

The _____________ is shown in Temperature-Specific Volume, TV projection:

Answer 10

Lines of Constant Pressure

Question 11

The change of phase of water illustrated in ___________ diagram

Answer 11

Temperature – Specific Volume Diagram

Question 12

are tables widely used by engineers and scientists in the design and operation of equipment where steam is used as a working substance in thermodynamic processes and cycles.

Answer 12

Steam tables

Question 13

Steam tables gives an idea about the phase of steam at various ______ and ______.

Answer 13

Temperature and Pressure

Question 14

_______ is the proportion by mass of vapor in a liquid-vapor mixture.

Answer 14

Steam quality

Question 15

A quality of zero (0) indicates 100% _________ while a quality of one (1) indicates 100% _________

Answer 15

Quality of 0 = 100% WATER
Quality of 1 = 100% STEAM

Question 16

It is one of the thermodynamic cycle that converts heat into work. Water is usually the working fluid of the cycle and heat is supplied externally in a closed system. WHAT IS THE CYCLE CALLED????????????????!!??!?!?

Answer 16

Rankine Cycle

Question 17

4 process of Rankine Cycle

Answer 17

Process 1-2: High pressure liquid enters the boiler and heat is added at a constant pressure until the working fluid becomes superheated vapor.

Process 2-3: The superheated vapor then goes to the turbine and expands isentropically. This process decreases the pressure and temperature, and condensation may occur.

Process 3-4: The wet vapor enters the condenser, where it is condensed at a constant pressure until it becomes saturated liquid.

Process 4-1: The saturated liquid is pumped from low to high pressure. At this stage, the pump requires low power input since the working fluid is liquid.

Question 18

___________ is the equation of state of an ideal gas. It is a good approximation of the behavior of gases in relation to its pressure, volume and temperature.

Answer 18

General Gas Law

Question 19

WHAT LAW??

If the temperature remains constant within a closed system, the volume of the gas varies ________ (inversely or directly) with the pressure during the change of state.

Answer 19

Boyle’s Law
INVERSELY

Question 20

WHAT LAW??

If the pressure remains constant within a closed system, the volume of the gas varies ________ (inversely or directly) with the temperature during the change of state.

Answer 20

Charles’s Law

DIRECTLY

Question 21

WHAT LAW??

The pressure of an ideal gas if held at a constant volume is _________ (inversely or directly) proportional to its temperature at any change of state.

Answer 21

Gay-Lussac’s Law

DIRECTLY

Question 22

What Principle states 1 mole of any ideal gas alyways occupies the same volume at a constant pressure and temperature

Answer 22

Avogadro’s Law

Question 23

One mole of ideal gas occupies how much volume? (english and SI units)

Answer 23

22.4 m^3
359 ft^3

Question 24

_______ is given by the Universal Gas Constant over the Molar Mass.

Answer 24

Ideal Gas Constant

Question 25

________ is a thermal property that measures the heat required to increase the temperature of one unit of thermodynamic substance by one degree.

Answer 25

Specific Heat

Question 26

Constant Volume Specific heat is equivalent to the change in _______

Answer 26

Internal Energy

Question 27

Constant Pressure Specific heat is equivalent to the change in _______

Answer 27

Enthalpy

Question 28

Specific heat of a gas at constant pressure (C_P) is greater than the specific heat at constant volume (C_V) because????

Answer 28

Unlike C_V , C_P is allowed to EXPAND at constant pressure, doing external work against expansion

C_P > C_V

Question 29

________ the ratio of specific heat at constant pressure and constant volume.

Answer 29

Isentropic Expansion

or

Specific heat ratio

Question 30

Problem 1: yes, may problem solving

An ideal gas with a mass of 2 kgs is contained in a 3.2 m3 rigid container. The initial temperature is 303 K and a pressure of 150 kPa. Determine the ideal gas constant.

Answer 30

(Ans. 0.7921 kJ/kg-K)

Question 31

Problem 2: yes, may problem solving

A rigid tank initially contains hydrogen initially at 100 kPa and 20oC. One and a half kilograms of hydrogen is added so that the final temperature and pressure of the tank is 30oC and 250 kPa, respectively. Determine the volume of the tank, in m3 and the final mass of the hydrogen inside the tank, in kgs. (RH2 = 4.125 kJ/kg-K)

Answer 31

(Ans. 12.79 m3, 2.56 kgs)

Question 32

Problem 3: yes, may problem solving

A pressurized vessel contains air at a gage pressure of 275 kPag and temperature of 28oC. If the bursting gage pressure of the vessel is found to be 1800 kPag, determine the temperature where the vessel will burst, in oC.

Answer 32

(Ans. 1697.18oC)

Question 33

Problem 4: yes, may problem solving

A 2-m3 rigid vessel contains helium initially at a gage pressure and temperature of 320 kPa and 315 K, respectively. Because of the leaks in the fittings of the vessel, the gage pressure dropped to 280 kPa and the temperature decreased to 300 K, determine the mass of the helium that leaked out and also the mass of nitrogen that remained in the vessel. (RHe = 2.077 kJ/kg-K)

Answer 33

(Ans. 0.06399 kg, 1.2240 kg)

Question 34

_____ occurs at a constant temperature. An example of this is a system immersed
in cooling water maintained at a constant temperature.

Answer 34

Isothermal Process

Question 35

n = 0 ; __ = C

Answer 35

P ; Isobaric Process

Question 36

n = Infinite ; __ = C

Answer 36

V; Isochoric Process

Question 37

n = 1 ; __ = C

Answer 37

T ; Isothermal Process

Question 38

Constant Pressure. What Process

Answer 38

Isobaric Process

Question 39

_____ are equipment where heat transfer between two different or similar fluids takes place. Heat transers occurs in an ____________ process

Answer 39

Heat Exchangers
Isobaric Process ; P = C