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What is thermodynamics?
What is thermodynamics?
The science of energy
What is the conservation of energy principle during an interaction?
What is the conservation of energy principle during an interaction?
Classical thermodynamics requires the knowledge of behavior of individual particles.
Classical thermodynamics requires the knowledge of behavior of individual particles.
False
Density is defined as ______ per unit volume.
Density is defined as ______ per unit volume.
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Match the equilibrium types with their definitions:
Match the equilibrium types with their definitions:
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According to the first law of thermodynamics, energy can be ________ during a process.
According to the first law of thermodynamics, energy can be ________ during a process.
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Define the net change in the total energy of a system during a process.
Define the net change in the total energy of a system during a process.
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Smog is primarily composed of ground-level oxygen (O3).
Smog is primarily composed of ground-level oxygen (O3).
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Match the following terms with their definitions:
Match the following terms with their definitions:
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What are some consequences of Tsat and Psat dependence for pure substances?
What are some consequences of Tsat and Psat dependence for pure substances?
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Define sublimation in the context of phase transitions of a pure substance.
Define sublimation in the context of phase transitions of a pure substance.
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At 1 atm pressure, the latent heat of fusion of water is __ kJ/kg and the latent heat of vaporization is __ kJ/kg.
At 1 atm pressure, the latent heat of fusion of water is __ kJ/kg and the latent heat of vaporization is __ kJ/kg.
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What is the portion of the internal energy associated with the kinetic energies of the molecules?
What is the portion of the internal energy associated with the kinetic energies of the molecules?
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What type of energy is associated with the atomic bonds in a molecule?
What type of energy is associated with the atomic bonds in a molecule?
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What is the energy associated with the phase of a system?
What is the energy associated with the phase of a system?
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What is the tremendous amount of energy associated with the strong bonds within the nucleus of an atom called?
What is the tremendous amount of energy associated with the strong bonds within the nucleus of an atom called?
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Which forms of energy make up mechanical energy?
Which forms of energy make up mechanical energy?
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Heat transfer is only recognized as heat when it crosses the system boundary.
Heat transfer is only recognized as heat when it crosses the system boundary.
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The work done is proportional to the force applied (F) and the distance traveled (s), therefore the formula for work when force is not constant is Work = ___ x Distance.
The work done is proportional to the force applied (F) and the distance traveled (s), therefore the formula for work when force is not constant is Work = ___ x Distance.
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What are the easily reproducible states that all temperature scales are based on?
What are the easily reproducible states that all temperature scales are based on?
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What is the Kelvin scale independent of?
What is the Kelvin scale independent of?
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Absolute pressure is measured relative to atmospheric pressure.
Absolute pressure is measured relative to atmospheric pressure.
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The pressure of a fluid at rest increases with depth due to the added ________.
The pressure of a fluid at rest increases with depth due to the added ________.
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Match the pressure measurement devices with their descriptions:
Match the pressure measurement devices with their descriptions:
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At what temperature does water freeze (or ice melt) according to the original Kelvin scale?
At what temperature does water freeze (or ice melt) according to the original Kelvin scale?
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What is the enthalpy of vaporization also known as?
What is the enthalpy of vaporization also known as?
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The ideal gas equation of state predicts the behavior of a gas accurately within any region.
The ideal gas equation of state predicts the behavior of a gas accurately within any region.
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What is the compressibility factor Z a measure of?
What is the compressibility factor Z a measure of?
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At very low pressures, all gases approach __________ behavior.
At very low pressures, all gases approach __________ behavior.
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What is the boundary work for a constant-volume process?
What is the boundary work for a constant-volume process?
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Are the units for specific heats cv and cp identical?
Are the units for specific heats cv and cp identical?
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The specific heat of a substance changes with temperature. True or False?
The specific heat of a substance changes with temperature. True or False?
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Is cp always greater than cv? Answer with 'yes' or 'no'.
Is cp always greater than cv? Answer with 'yes' or 'no'.
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Which property is conserved during a process according to the text?
Which property is conserved during a process according to the text?
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Define volume flow rate.
Define volume flow rate.
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During a steady-flow process, the total amount of mass contained within a control volume does not change with time, thus indicating that mass flow rate is ____.
During a steady-flow process, the total amount of mass contained within a control volume does not change with time, thus indicating that mass flow rate is ____.
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In a two-inlet–one-outlet steady-flow system, the conservation of mass principle requires the total amount of mass entering to equal the total amount leaving.
In a two-inlet–one-outlet steady-flow system, the conservation of mass principle requires the total amount of mass entering to equal the total amount leaving.
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Match the following components with their definitions:
Match the following components with their definitions:
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Study Notes
Introduction to Thermodynamics
- Thermodynamics is the science of energy
- Energy is the ability to cause changes
- The name "thermodynamics" stems from the Greek words "therme" (heat) and "dynamis" (power)
Laws of Thermodynamics
- The first law of thermodynamics: energy cannot be created or destroyed, only converted from one form to another
- The second law of thermodynamics: energy has quality as well as quantity, and actual processes occur in the direction of decreasing quality of energy
Systems and Control Volumes
- System: a quantity of matter or a region in space chosen for study
- Surroundings: the mass or region outside the system
- Boundary: the real or imaginary surface that separates the system from its surroundings
- Closed system (control mass): a fixed amount of mass, and no mass can cross its boundary
- Open system (control volume): a properly selected region in space that involves mass flow
Properties
- Property: any characteristic of a system
- Intensive properties: independent of the mass of a system (e.g., temperature, pressure, density)
- Extensive properties: dependent on the size or extent of the system
- Specific properties: extensive properties per unit mass
- Continuum idealization: treating a substance as a continuous, homogeneous matter with no holes or gaps
State and Equilibrium
- Thermodynamics deals with equilibrium states
- Equilibrium: a state of balance
- Thermal equilibrium: the temperature is the same throughout the entire system
- Mechanical equilibrium: no change in pressure at any point of the system with time
- Phase equilibrium: a system involves two phases and the mass of each phase reaches an equilibrium level and stays there
- Chemical equilibrium: the chemical composition of a system does not change with time
Processes and Cycles
- Process: any change that a system undergoes from one equilibrium state to another
- Path: the series of states through which a system passes during a process
- Quasistatic or quasi-equilibrium process: a process that proceeds in such a manner that the system remains infinitesimally close to an equilibrium state at all times
- Isothermal process: a process during which the temperature remains constant
- Isobaric process: a process during which the pressure remains constant
- Isochoric (or isometric) process: a process during which the specific volume remains constant
- Cycle: a process during which the initial and final states are identical
Temperature and the Zeroth Law of Thermodynamics
- Temperature: a measure of the thermal motion of molecules
- Zeroth law of thermodynamics: if two bodies are in thermal equilibrium with a third body, they are also in thermal equilibrium with each other
- Temperature scales: Celsius, Fahrenheit, Kelvin, and Rankine
Pressure
- Pressure: a normal force exerted by a fluid per unit area
- Absolute pressure: the actual pressure at a given position
- Gage pressure: the difference between the absolute pressure and the local atmospheric pressure
- Vacuum pressures: pressures below atmospheric pressure
- Pascal's law: the pressure applied to a confined fluid increases the pressure throughout by the same amount
Measurement of Pressure
- Manometer: a device used to measure small and moderate pressure differences
- Bourdon tube: a type of pressure transducer
- Piezoelectric transducers: use the principle that an electric potential is generated in a crystalline substance when it is subjected to mechanical pressure
Atmospheric Pressure and Barometers
- Atmospheric pressure: the pressure exerted by the atmosphere on the surface of the Earth
- Barometer: a device used to measure atmospheric pressure
- Standard atmosphere: a unit of pressure defined as the pressure produced by a column of mercury 760 mm in height at 0°C### Thermodynamics and Energy
- Application areas of thermodynamics include energy conversion, power generation, and transportation systems
- Importance of dimensions and units in thermodynamics, including SI and English units
- Dimensional homogeneity and unity conversion ratios in thermodynamics
Systems and Control Volumes
- A system is a quantity of matter or a region in space where a process takes place
- A control volume is a fixed region in space where energy and mass balances are applied
- Properties of a system include density and specific gravity
- State and equilibrium of a system
Temperature and the Zeroth Law of Thermodynamics
- Temperature scales, including Celsius, Fahrenheit, and Kelvin
- The zeroth law of thermodynamics states that if two systems are in thermal equilibrium with a third system, they are also in thermal equilibrium with each other
Energy and Energy Transfer
- Forms of energy include thermal, mechanical, kinetic, potential, electric, magnetic, chemical, and nuclear
- Energy can be transferred as heat, work, and mass
- The first law of thermodynamics states that energy cannot be created or destroyed, only converted from one form to another
The First Law of Thermodynamics
- The first law is a statement of energy conservation, stating that the energy change of a system is equal to the net heat transfer and work done on the system
- Energy balance equations for a system, including internal, kinetic, and potential energy changes
Energy Conversion Efficiencies
- Efficiency is a measure of how well an energy conversion or transfer process is accomplished
- Examples of energy conversion efficiencies include the efficiency of a water heater and the annual fuel utilization efficiency (AFUE) of space heating systems
Types of Energy
- Mechanical energy: the energy associated with the motion and position of an object
- Thermal energy: the energy associated with the temperature of an object
- Electrical energy: the energy associated with the movement of charged particles
- Nuclear energy: the energy associated with the nucleus of an atom
Heat Transfer
- Heat transfer mechanisms: conduction, convection, and radiation
- Heat transfer equations, including heat transfer rate and heat transfer per unit mass
Work Transfer
- Work transfer mechanisms: mechanical work, electrical work, and magnetic work
- Work transfer equations, including work done per unit mass and power### Energy Conversion Efficiencies
- A generator is a device that converts mechanical energy to electrical energy
- Generator efficiency is the ratio of electrical power output to mechanical power input
- Thermal efficiency of a power plant is the ratio of net electrical power output to rate of fuel energy input
- Overall efficiency of a power plant is the product of the turbine efficiency and generator efficiency
Energy and Environment
- Energy conversion processes often affect the environment and air quality
- Pollutants emitted during fossil fuel combustion cause smog, acid rain, and global warming
- Motor vehicles are the largest source of air pollution
- Energy conversion processes are often accompanied by environmental pollution
Ozone and Smog
- Smog is made up of ground-level ozone (O3), carbon monoxide (CO), particulate matter, and volatile organic compounds (VOCs)
- Ground-level ozone is formed when hydrocarbons (HC) and nitrogen oxides (NOx) react in the presence of sunlight
- Ozone irritates eyes and damages lungs, causing shortness of breath, wheezing, fatigue, headaches, and nausea
- Carbon monoxide is a colorless, odorless, poisonous gas that deprives the body's organs of oxygen
Acid Rain
- Sulfur in fuel reacts with oxygen to form sulfur dioxide (SO2), an air pollutant
- Sulfur oxides and nitric oxides react with water vapor and other chemicals to form sulfuric and nitric acids
- Acid rain is formed when these acids dissolve in suspended water droplets in clouds or fog
- Acid rain affects soil, vegetation, and wildlife, and can also damage buildings and infrastructure
The Greenhouse Effect and Global Warming
- The greenhouse effect occurs when carbon dioxide (CO2), water vapor, and other gases trap heat in the atmosphere
- The main sources of CO2 emissions are fossil fuel combustion, deforestation, and land-use changes
- Global warming can cause severe weather patterns, flooding, and droughts, as well as rising sea levels and loss of wetlands and coastal areas
- Renewable energy sources such as wind and solar power can help minimize global warming
Properties of Pure Substances
- A pure substance has a fixed chemical composition throughout
- Air is considered a pure substance, although it is a mixture of gases
- Nitrogen and gaseous air are pure substances
- A mixture of liquid and gaseous water is a pure substance, but a mixture of liquid and gaseous air is not
Phases of a Pure Substance
- In a solid, molecules are kept at relatively fixed positions by intermolecular forces
- In a liquid, groups of molecules move about each other
- In a gas, molecules move about randomly
- The arrangement of atoms in different phases: solid, liquid, and gas
Phase-Change Processes of Pure Substances
- Compressed liquid: a substance that is not about to vaporize
- Saturated liquid: a liquid that is about to vaporize
- Saturated vapor: a vapor that is about to condense
- Superheated vapor: a vapor that is not about to condense
Thermodynamics: An Engineering Approach
- Thermodynamics is the study of energy and its interactions with matter
- The first law of thermodynamics states that energy cannot be created or destroyed, only converted from one form to another
- The second law of thermodynamics states that the total entropy of an isolated system always increases over time
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Description
This quiz covers the introduction and basic concepts of thermodynamics, including the definition of key terms and concepts.
