Thermodynamics Basics

Questions and Answers

What is the main focus of thermodynamics?

Mathematical concepts

Matter and its properties

Physical properties of substances

Energy and its transformation (correct)

What is the definition of a thermodynamic system?

A region in space chosen for study (correct)

A real or imaginary surface separating the system from the surrounding

The mass and region outside the system

The quantity of matter or energy

What type of system has a fixed amount of mass and no mass can cross its boundary?

Thermodynamic System

Open System

Closed System (correct)

Control Volume

What is the boundary of a control volume called?

Control Surface Signup and view all the answers

What is the macroscopic approach in thermodynamics?

Considering a certain quantity of matter without taking into account the events occurring at the molecular level Signup and view all the answers

What is the main characteristic of a macroscopic system?

It can be easily measured Signup and view all the answers

What is the primary focus of classical thermodynamics?

Macroscopic approach Signup and view all the answers

What is the main difference between a closed system and an open system?

Mass can cross the boundary in an open system Signup and view all the answers

What is the approach that considers the matter to be comprised of tiny particles known as molecules?

Microscopic approach Signup and view all the answers

Which property is independent of the size of the system?

Temperature Signup and view all the answers

What is the term for the quotient of the substance's volume to its mass?

Specific volume Signup and view all the answers

What is the state of a system described by?

Its properties Signup and view all the answers

What is the condition of a system at any instant of time called?

State Signup and view all the answers

What is the term for a system that has no unbalanced potentials within the system?

Equilibrium state Signup and view all the answers

What is the term for the series of states through which a system passes during a process?

Path Signup and view all the answers

Which property is dependent on the size or extent of the system?

Mass Signup and view all the answers

What is the term for a continuous, homogeneous matter with no holes?

Continuum Signup and view all the answers

What is the term for the density of a substance with respect to the density of some standard substance?

Specific gravity Signup and view all the answers

What is the characteristic of a quasi-equilibrium process?

The system remains infinitesimally close to an equilibrium state at all times. Signup and view all the answers

What is the difference between a point function and a path function?

A point function is a quantity whose value is independent of the path, while a path function is a quantity whose value depends on the path. Signup and view all the answers

What is the definition of a cycle?

A process that returns the system to its initial state. Signup and view all the answers

What is the unit of pressure in the SI system?

N/m2 Signup and view all the answers

What is the definition of thermodynamic equilibrium?

A state where there are no changes in macroscopic properties. Signup and view all the answers

What is the condition for mechanical equilibrium?

There is no change in pressure at any point of the system. Signup and view all the answers

What is the relationship between the Kelvin and Celsius temperature scales?

T(K) = T(C) + 273.16 Signup and view all the answers

What is the definition of absolute pressure?

The pressure measured relative to absolute vacuum. Signup and view all the answers

What is the difference between gauge pressure and absolute pressure?

Gauge pressure is the pressure measured relative to atmospheric pressure, while absolute pressure is the pressure measured relative to absolute vacuum. Signup and view all the answers

What is the relationship between the Rankine and Fahrenheit temperature scales?

T(R) = T(F) + 459.67 Signup and view all the answers

What is the characteristic feature of a quasi-static process?

Infinite slowness Signup and view all the answers

What is the condition for a reversible process?

No dissipative effects Signup and view all the answers

What is the formula for calculating work in physics?

W=F·d·cos(θ) Signup and view all the answers

What is the sign convention for work done by the system in thermodynamics?

Positive Signup and view all the answers

What is the characteristic of an irreversible process?

Net change occurs in the Universe Signup and view all the answers

What is pressure-volume work?

Work done by a system at constant pressure Signup and view all the answers

What is the condition for chemical equilibrium?

No chemical reaction occurs Signup and view all the answers

What is the unit of work in the International System of Units (SI)?

Joule Signup and view all the answers

What is the formula for thermodynamic work?

W=P·V Signup and view all the answers

What is the definition of thermodynamic work?

Work is said to be done by a system if the sole effect on things external to the system can be reduced to the raising of a weight. Signup and view all the answers

What is the primary focus of thermodynamics in terms of energy?

Energy conversion and its effect on physical properties Signup and view all the answers

Which of the following is a characteristic of a closed system?

Energy can cross its boundary Signup and view all the answers

What is the term for a region in space chosen for study in thermodynamics?

System Signup and view all the answers

Which approach considers a certain quantity of matter without taking into account the events occurring at the molecular level?

Macroscopic approach Signup and view all the answers

What is considered in the microscopic approach of thermodynamics?

A large number of tiny particles known as molecules Signup and view all the answers

What is the term for the surface that separates a control volume from the surrounding?

Control surface Signup and view all the answers

Which of the following is an intensive property?

Temperature Signup and view all the answers

What is the characteristic of an open system?

Both mass and energy can cross its boundary Signup and view all the answers

What is specific volume?

The reciprocal of density Signup and view all the answers

What is the focus of classical thermodynamics?

Macroscopic level Signup and view all the answers

What is the condition for a system to be in equilibrium?

There are no unbalanced potentials within the system Signup and view all the answers

Which of the following is an example of a closed system?

Piston cylinder device Signup and view all the answers

What is the primary characteristic of thermodynamic studies?

Equilibrium and feasibility Signup and view all the answers

What is a process in thermodynamics?

A change from one equilibrium state to another Signup and view all the answers

Which of the following is a characteristic of a system in thermodynamic equilibrium?

Balanced potentials within the system Signup and view all the answers

What is a characteristic of an extensive property?

Dependent on the size or extent of the system Signup and view all the answers

What is the term for the density of a substance with respect to the density of some standard substance?

Specific gravity Signup and view all the answers

What is continuum?

A continuous, homogeneous matter with no holes Signup and view all the answers

What is the state of a system?

Described by its properties Signup and view all the answers

What is a characteristic of intensive properties?

Not additive Signup and view all the answers

What is the characteristic of a quasi-equilibrium process?

It is an idealized process that remains infinitesimally close to an equilibrium state Signup and view all the answers

What is the difference between a point function and a path function?

Point functions are exact differentials, while path functions are inexact differentials Signup and view all the answers

What is a cycle?

A process where the system returns to its initial state Signup and view all the answers

What is the unit of pressure in the SI system?

Pascal Signup and view all the answers

What is thermodynamic equilibrium?

A state where no changes in macroscopic properties are observed Signup and view all the answers

What is the characteristic feature of a quasi-static process?

Infinite slowness Signup and view all the answers

What is a reversible process?

A process that is performed infinitely slowly with infinitesimal gradient Signup and view all the answers

What is the condition for mechanical equilibrium?

No change in pressure at any point of the system Signup and view all the answers

What is an irreversible process?

A process that is carried out in such a way that the system and surrounding cannot be exactly restored to their respective initial state at the end of the reverse process Signup and view all the answers

What is the relationship between the Kelvin and Celsius temperature scales?

T(K) = T(C) + 273.16 Signup and view all the answers

What is the formula for calculating work in physics?

W=F·d·cos(?) Signup and view all the answers

What is absolute pressure?

The pressure measured relative to absolute vacuum Signup and view all the answers

What is pressure-volume work?

Work involved in a change in volume or pressure, typically involving gas Signup and view all the answers

What is the difference between gauge pressure and absolute pressure?

Gauge pressure is the pressure measured relative to atmospheric pressure, while absolute pressure is the pressure measured relative to absolute vacuum Signup and view all the answers

What is the sign convention for work done by the system in thermodynamics?

Work done by the system is considered positive Signup and view all the answers

What is the relationship between the Rankine and Fahrenheit temperature scales?

T(R) = T(F) + 459.67 Signup and view all the answers

What is the condition for chemical equilibrium?

The system's composition does not change with time Signup and view all the answers

What is the unit of work in the International System of Units (SI)?

Joule Signup and view all the answers

What is the formula for thermodynamic work?

W=P·V Signup and view all the answers

What is the characteristic of a reversible process in terms of heat and work interactions?

Heat and work interactions are always equal and opposite in direction Signup and view all the answers

Study Notes

Introduction to Thermodynamics

Thermodynamics is the science of energy and its transformation, and its effects on physical properties of substances.
It deals with equilibrium and feasibility of a process, and the relationship between heat and work, and the properties of systems in equilibrium.

Thermodynamics System

A thermodynamics system is defined as a quantity of matter or a region in space chosen for study.
The mass and region outside the system is called the surrounding.
The boundary of the system is a real or imaginary surface that separates the system from the surrounding.

Types of Thermodynamics Systems

Closed System (Control Mass): A fixed amount of mass, no mass can cross its boundary, and energy can cross the boundary in the form of heat or work.
Open System (Control Volume): A properly selected region in space where both mass and energy can cross the boundary.

Approaches to Thermodynamics

Macroscopic Approach: Considers a certain quantity of matter without taking into account events occurring at the molecular level.
Microscopic Approach: Considers the matter as comprised of a large number of tiny particles known as molecules, which move randomly in a disordered fashion.

Properties of a System

Property: Any characteristic of a system.
Intensive Properties: Independent of the size of the system, such as temperature, pressure, and density.
Extensive Properties: Depend on the size or extent of the system, such as mass, volume, and total energy.

Specific Properties of a System

Specific Properties: Extensive properties per unit mass.
Specific Volume: The volume of a substance per unit mass.
Specific Energy: The energy of a substance per unit mass.
Specific Gravity: The density of a substance with respect to the density of a standard substance at a specified temperature.

Continuum and State

Continuum: A continuous, homogeneous matter with no holes.
State: The condition of a system at any instant of time, described by its properties.

Equilibrium and Processes

Equilibrium: A state of balance, with no unbalanced potentials or driving forces within the system.
Process: A change that a system undergoes from one equilibrium state to another.
Quasi-Equilibrium Process: A process that proceeds in a manner that the system remains infinitesimally close to an equilibrium state at all times.

Point Function and Path Function

Point Function: A quantity whose change is independent of the path, such as properties.
Path Function: A quantity whose value depends on the path followed during a change of state, such as heat and work.

Cycle and Steady Flow Process

Cycle: A system that returns to its initial state at the end of a process.
Steady Flow Process: A process during which a fluid flows through a control volume steadily.

Temperature and Pressure

Temperature: A measure of hotness or coldness, measured in Celsius or Kelvin scales.
Pressure: The force exerted by a fluid per unit area, measured in pascals.

Thermodynamic Equilibrium

Thermodynamic Equilibrium: A system that exists in a state of equilibrium, with no changes in macroscopic properties observed if the system is isolated from its surroundings.

Quasi-Static Process and Reversible Process

Quasi-Static Process: A process that is performed in an infinitesimally slow manner, with the system remaining in equilibrium at all times.
Reversible Process: A process that is performed in such a way that both the system and surrounding can be restored to their initial state without producing any changes in the rest of the universe.

Irreversible Process

Irreversible Process: A process that is carried out in such a way that the system and surrounding cannot be exactly restored to their respective initial states at the end of the reverse process.

Work in Thermodynamics

Work: The transfer of energy that occurs when a force is applied to an object, causing it to move.
Thermodynamic Work: Work involves energy transfer that occurs when a system undergoes a change in volume or pressure.
Pressure-Volume Work: Work done by or on a system at constant pressure, given by W = PΔV.

Sign Convention and Heat Transfer

Sign Convention: Work done by the system is positive, and work done on the system is negative.
Heat Transfer: The transfer of energy from one body to another due to a temperature difference.