Thermodynamic Property Tables and Charts: Master the Basics for Engineering Success

Question 1

Which of the following is NOT a thermodynamic property table?

Accepted Answer

P-v Diagram

Answer

Steam Table

Answer

Mollier Diagram

Answer

Air Table

Question 2

Which of the following diagrams is used to represent the relationship between pressure and specific volume?

Accepted Answer

P-v diagram

Answer

T-s diagram

Answer

h-s diagram

Answer

Mollier diagram

Question 3

Which of the following substances has the highest specific heat capacity?

Accepted Answer

Water

Answer

Air

Answer

Iron

Answer

Copper

Question 4

What is the entropy change of a closed system undergoing a reversible isothermal process?

Accepted Answer

Zero

Answer

Positive

Answer

Negative

Answer

Cannot be determined

Question 5

What is the difference between the ideal gas law and the van der Waals equation?

Accepted Answer

The van der Waals equation accounts for intermolecular forces and finite molecular volume, while the ideal gas law does not.

Answer

The ideal gas law accounts for intermolecular forces and finite molecular volume, while the van der Waals equation does not.

Answer

They are both valid under all conditions.

Answer

They cannot be compared as they are used for different purposes.

Question 6

Which of the following charts is not typically used in thermodynamics?

Accepted Answer

Venn Diagram

Answer

Mollier Diagram

Answer

Psychrometric Chart

Answer

T-s Diagram

Question 7

The reduced pressure of a substance is defined as the ratio of:

Accepted Answer

Actual pressure to critical pressure

Answer

Actual temperature to critical temperature

Answer

Critical pressure to actual pressure

Answer

Critical temperature to actual temperature

Question 8

Which thermodynamic properties can be directly obtained from a steam table?

Accepted Answer

Enthalpy, entropy, and specific volume

Answer

Pressure, temperature, and volume

Question 9

Which of the following is NOT a source of thermodynamic property data?

Accepted Answer

Dimensional analysis

Answer

Steam tables

Answer

Mollier charts

Answer

Psychometric charts

Question 10

What is the significance of the saturation line on a pressure-enthalpy chart?

Accepted Answer

Indicates the boundary between saturated liquid and saturated vapor regions

Answer

Represents the critical point of the substance

Answer

Shows the path of an isentropic process

Answer

Indicates the melting and boiling points of the substance

Question 11

What is the key distinction between a saturated vapor and a superheated vapor?

Accepted Answer

Saturated vapor exists at its boiling point, while superheated vapor is at a higher temperature

Answer

Saturated vapor contains liquid droplets, while superheated vapor does not

Answer

Saturated vapor has a lower specific volume than superheated vapor

Answer

Saturated vapor cannot be compressed, while superheated vapor can

Question 12

Which thermodynamic property is independent of the path taken by the system (i.e., path independent)?

Accepted Answer

Specific entropy

Answer

Specific enthalpy

Answer

Specific volume

Answer

Temperature

Question 13

What is the significance of the triple point on a phase diagram?

Accepted Answer

Represents the state where solid, liquid, and vapor phases coexist in equilibrium

Answer

Indicates the critical point of the substance

Answer

Shows the melting and boiling points of the substance

Answer

Represents the state of lowest density for the substance

Question 14

Which of the following processes is represented by a constant-temperature line on a pressure-volume diagram?

Accepted Answer

Isothermal

Answer

Adiabatic

Answer

Isentropic

Answer

Isochoric

Question 15

What is the primary purpose of using a Mollier chart?

Accepted Answer

To determine the enthalpy change of a process

Answer

To calculate the work done by a system

Answer

To find the entropy change of a process

Answer

To identify the phase of a substance

Question 16

What is the defining characteristic of a saturated liquid?

Accepted Answer

It exists in equilibrium with its vapor phase

Answer

It is at its boiling point

Answer

It has a specific enthalpy equal to the latent heat of vaporization

Answer

It is at its maximum density

Question 17

What is the significance of the critical point on a thermodynamic property chart?

Accepted Answer

It is the point at which the liquid and vapor phases become indistinguishable

Answer

It represents the highest temperature and pressure at which a substance can exist as a liquid

Answer

It indicates the transition from a liquid to a gas

Answer

It is the point of maximum specific volume for a substance

Question 18

In a thermodynamic property table for water, which column contains the specific heat at constant pressure?

Accepted Answer

Specific Heat at Constant Pressure

Answer

Temperature

Answer

Pressure

Answer

Specific Enthalpy

Question 19

When using a pressure-enthalpy chart, isobaric lines represent which of the following?

Accepted Answer

Constant pressure

Answer

Constant temperature

Answer

Constant specific volume

Answer

Constant specific entropy

Question 20

In an isentropic process represented on a T-s diagram, which property remains constant?

Accepted Answer

Entropy

Answer

Temperature

Answer

Pressure

Answer

Volume

Question 21

How is the specific heat capacity at constant pressure defined?

Accepted Answer

Heat required to raise the temperature of 1 unit mass of a substance by 1 unit temperature at constant pressure

Answer

Heat required to raise the temperature of 1 mole of a substance by 1 unit temperature at constant pressure

Answer

Heat required to change the phase of 1 unit mass of a substance by 1 unit temperature at constant pressure

Answer

Heat required to change the volume of 1 unit mass of a substance by 1 unit volume at constant pressure

Question 22

In thermodynamic property tables, the specific volume of a substance is typically reported in:

Accepted Answer

Cubic meters per kilogram

Answer

Liters per gram

Answer

Cubic feet per pound

Answer

Gallons per cubic foot

Question 23

How can the Clapeyron equation be used to determine the slope of the vapor-pressure curve on a phase diagram? Explain your reasoning.

Accepted Answer

The Clapeyron equation relates the change in vapor pressure to the change in temperature and the enthalpy of vaporization.

Answer

The slope of the vapor-pressure curve can be directly calculated using saturation pressure and temperature data.

Answer

The ideal gas law can be used to estimate the slope, assuming constant specific volume.

Answer

The Clapeyron equation can be used to find the slope of the coexistence line between liquid and vapor phases.

Question 24

Which of the following is NOT a common type of thermodynamic property table?

Accepted Answer

Reaction Equilibrium Constant

Answer

Mollier

Answer

Psychometric

Answer

Vapor Pressure

Question 25

The enthalpy of a substance at a given temperature and pressure can be obtained from a:

Accepted Answer

Enthalpy Table

Answer

Entropy Chart

Answer

Specific Heat Capacity Table

Question 26

The process of interpolating property data between two known values in a table or chart is called:

Accepted Answer

Interpolation

Answer

Extrapolation

Answer

Numerical Integration

Answer

Differentiation

Question 27

Which of the following is an assumption made when using thermodynamic property tables and charts?

Accepted Answer

Substance is in equilibrium

Answer

Process is reversible

Answer

Substance is incompressible

Answer

Heat transfer is negligible

Question 28

The critical temperature of a substance can be found using:

Accepted Answer

Vapor Pressure Chart

Answer

Mollier Diagram

Answer

Entropy Table

Answer

Temperature-Volume Chart

Question 29

Which property chart is commonly used for analyzing power plant cycles?

Accepted Answer

Enthalpy-Entropy Chart

Answer

Pressure-Volume Chart

Answer

Vapor Pressure Chart

Question 30

Which of the following is a limitation of thermodynamic property tables and charts?

Accepted Answer

Limited to specific substances and states

Answer

Can be easily updated for new substances

Answer

Provide highly accurate data

Question 31

What is the primary purpose of using a property chart?

Accepted Answer

To obtain property data for a substance at a specific state

Answer

To determine the phase of a substance

Answer

To calculate thermodynamic efficiency

Question 32

What is the key distinction between a saturation curve and a constant-pressure line on a pressure-enthalpy diagram?

Accepted Answer

The saturation curve represents the liquid-vapor coexistence state, while the constant-pressure line does not.

Answer

The saturation curve shows higher enthalpy values than the constant-pressure line.

Question 33

Which of the following is a potential limitation of using property tables?

Accepted Answer

They only provide discrete property values for certain conditions.

Answer

They are not applicable to real-world systems.

Answer

They are difficult to interpolate between data points.

Question 34

In the context of property tables, which interpolation method is commonly used to estimate property values between data points?

Accepted Answer

Linear interpolation

Answer

Quadratic interpolation

Answer

Cubic interpolation

Answer

Logarithmic interpolation

Question 35

Which software application is widely used by engineers to access and manipulate thermodynamic property data?

Accepted Answer

REFPROP

Answer

ANSYS Fluent

Answer

SolidWorks

Answer

MATLAB

Question 36

What is the significance of the critical point on a thermodynamic property diagram?

Accepted Answer

It represents the point at which the liquid and vapor states become indistinguishable.

Answer

It is the point at which the substance has the highest density.

Answer

It indicates the maximum temperature at which the substance can exist as a liquid.

Question 37

A saturated liquid-vapor mixture of water is at 100°C. Which property CANNOT be directly obtained from a saturated water table at 100°C?

Accepted Answer

Specific enthalpy of the mixture

Answer

Specific entropy of the saturated vapor

Answer

Specific volume of the saturated liquid

Answer

Specific enthalpy of the saturated vapor

Question 38

A superheated steam table provides data for:

Accepted Answer

Steam at temperatures higher than the saturation temperature for a given pressure

Answer

Saturated liquid-vapor mixtures at various pressures

Answer

Liquid water at temperatures below the saturation temperature

Question 39

In Mollier diagrams, which thermodynamic property is typically used as the independent variable?

Accepted Answer

Enthalpy

Answer

Pressure

Answer

Temperature

Answer

Entropy

Question 40

During a throttling process, which thermodynamic property of a refrigerant remains approximately constant?

Accepted Answer

Enthalpy

Answer

Entropy

Answer

Temperature

Answer

Pressure

Question 41

In a pressure-enthalpy (P-h) diagram for R-134a, which property is NOT typically presented?

Accepted Answer

Specific volume

Answer

Enthalpy

Answer

Pressure

Answer

Temperature

Question 42

Air is compressed adiabatically from 1 atm to 5 atm. What is the most effective method for determining the final air temperature?

Accepted Answer

Using an isentropic efficiency value and a compressor map

Answer

Directly from a compressed air table at 5 atm

Answer

By assuming constant specific heat and using the polytropic process equation

Question 43

What is the primary advantage of using a thermodynamic property chart (like a Mollier diagram) over a table?

Accepted Answer

Visual representation of property relationships and process paths

Answer

More accurate data for specific applications

Answer

Easier to interpolate between data points

Question 44

A steam power plant operates with a condenser pressure of 10 kPa. Which property is crucial for determining the quality of steam exiting the condenser?

Accepted Answer

Specific enthalpy

Answer

Specific volume

Answer

Temperature

Answer

Specific entropy

Question 45

An air conditioning system uses a refrigerant at 5°C and 1.5 bar. What is the most suitable resource for determining the refrigerant's specific enthalpy under these conditions?

Accepted Answer

Refrigerant property table at 1.5 bar

Answer

Mollier diagram for the refrigerant

Answer

Psychrometric chart at 5°C

Answer

Superheated steam table at 5°C