Thermodynamics 4
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Complete list of Terms and Definitions for Thermodynamics 4

Terms Definitions
Flats ΔH=nΔHvap
heat transferred q=
celsius temperature scale
delta U (3/2)nR(delta T)
Solid a three-dimensional shape
Thermodynamics movement of heat
Subatomic Particles Protons, Neutrons, electrons
state function ΔH is a...
kinetic energy energy of motion
Control mass (see closed system).
System doing work Negative (-)
Delta G = 0 At Equilibrium
endothermic absorb thermal energy from surroundings
4.18J 1 calorie (c) -> J
low heats/cools quick if q is
Calorimetry the measurement of heat transferred
Work done to system Positive (+)
Heat capacity of liquid water 4.18 J/gC
Protons particles with posative charge located in nucleus
conservation of energy First law of thermodynamics
exothermic energy flows from system to surroundings
Spontaneous Change a change that occurs naturally
Units are the arbitrary magnitudes assigned to the dimensions.
gold a precious yellow metallic element, highly malleable and ductile, and not subject to oxidation or corrosion.
1st law Energy is not created or destroyed
fusion the act of fusing (or melting) together
heat content At constant pressure, changes in enthalpy accompanying a reaction are measures of changes in ____ _____ (two words) in the system.
heat transfer of kinetic energy from a hotter object to a colder object
K-value A numeric expression of a material's ability to conduct heat energy on a unit-thickness basis.
enthalpy heat absorbed or released from a chemical reaction under constant pressure. (cannot be measured directly, so we measure delta H)
Overall efficiency (combined efficiency) for a power plant is defined as the ratio of the net electrical power output to the rate of fuel energy input and is expressed as the product of the combustion efficiency, thermal efficiency and generator efficiency.
Frosting which occurs in humid climates when the temperature falls below 2 to 5°C, is the major problem with air-source systems. The frost accumulation on the evaporator coils is highly undesirable since it seriously disrupts heat transfer. The coils can be defrosted, however, by reversing the heat pump cycle (running it as an air conditioner). This results in a reduction in the efficiency of the system.
Vacuum pressure is the pressure below atmospheric pressure and is measured by a vacuum gage that indicates the difference between the atmospheric pressure and the absolute pressure.
Thermodynamic State condition in which the measurable properties as a defined value
h u + pv --(internal energy + pressure*specific volume
Positive or 0 ∆G These processes are never spontaneous.
calorie unit of heat defined as the quantity of heat required to raise the temperature of 1 gram of water by 1 degree centigrade at atmospheric pressure (between 14.5 and 15.5°C)
Breathing oxygen comes from the spitting of water during photosystem II to replace electrons.
calorimeter a device used to determine the heat associated with a chemical reaction
thermochemical equation equation that includes the quantity of energy released or absorbed as heat during the reaction
Standard Conditions Conditions at which gas pressure is 1.0 atm (103.3 kPa), the concentrations of dissolved species are 1.0M and the temperature is 25*C
Conduction the direct transfer of heat from one substance to another substance that it is touching
entropy the measure of the amount of disorder in a reaction
Heat Capacity Amount of heat required to raise temperature of system through 1 degree (Celsius or Kelvin).
Immediate surroundings refer to the portion of the surroundings that is affected by the process.
Throat is the smallest flow area of a converging-diverging nozzle.
Expansion fan is a continuous expanding region of supersonic flow composed of an infinite number of Mach waves called Prandtl-Meyer expansion waves.
Iso-prefix is often used to designate a process for which a particular property remains constant.
Gage pressure is the difference between the absolute pressure and the local atmospheric pressure.
Clapeyron equation named after the French engineer and physicist E. Clapeyron (1799-1864), relates the enthalpy change associated with a phase change (such as the enthalpy of vaporization hfg) from knowledge of P, v, andT data alone.
Enthalpy H (from the Greek word enthalpien, which means to heat)is a property and is defined as the sum of the internal energy U and the PV product.
spontaneous a reaction that does occur or is likely to occur without continuous outside assistance, such as input of energy. Ex:) an avalanche, combustion reactions, etc.
temperature (T) measure of the average kinetic energy of the particles in a system
equilibrium or phase change Where ΔG degrees is zero (spon?)
Isovolumetric Process change in temperature but no change in volume. No WORK is BEING DONE! change in U equal Q energy added to the system as heat increases the system's internal energy likewise with energy removed from the system as heat decreases the system's internal energy
Specific Heat the amount of energy required to raise the temperature of 1 kilogram of a material by 1 kelvin
At a given state, each property has a definite value that can be assigned without knowledge of how the system arrived at that state. True or False. True
heat of formation given for standeard states of a compound (1 atm, 298.15K or 25C); for compounds: highly negative values are stable, slightly negative or positive values are not stable, highly positive values are very unstable
Spontaneous Reaction a reaction that causes a release in free energy and occurs without being driven by an outside source
Heat of vaporization liquid to gas or gas to liquid
Propulsive power is the power developed from the thrust of the aircraft gas turbines and is the propulsive force (thrust) times the distance this force acts on the aircraft per unit time, that is, the thrust times the aircraft velocity.
Regenerator effectiveness is the extent to which a regenerator approaches an ideal regenerator and is defined as the ratio of the heat transfer to the compressor exit gas to the maximum possible heat transfer to the compressor exit gas.
Thermoelectric generator uses the Seebeck effect as the basis for thermoelectric power generation.
Pressure ratio is the ratio of final to initial pressures during a compression process.
Process heat is required energy input in the form of heat for many industrial processes. The process heat is often obtained as heat transfer from high-pressure, high-temperature steam. Some industries that rely heavily on process heat are chemical, pulp and paper, oil production and refining, steel making, food processing, and textile industries.
delta H sum of heats of formation for products - sum of heats fo reactants
What is a radiation inversion? Radiative cooling near surface, tend to be shallow, most pronounced on cold, clear , calm nights.
Photo Respiration A loss of carbon and water through the leaves of a plant during photosyntesis.
molar heat of formation energy released or absorbed as heat when 1 mole of a compound is formbed by combination of its elements
Electromagnetic Waves a form of energy that can move through the vacuum of space
Extensive Property One that depends on the total size or total mass of the system (Ex.: volume, mass)
Mach angle is the shock angle for Mach waves and is a unique function of the Mach number.
Working fluid is the fluid to and from which heat and work is transferred while undergoing a cycle in heat engines and other cyclic devices.
Prandtl-Meyer expansion waves are the Mach waves that compose a continuous expanding region called an expansion fan.
Intensive Properties: E, G, T, P properties of thermodynamic state which do not depend on the amount of material
2nd law of thermodynamics Heat never spontaneously flows from a cold substance to a hot substance.
ΔG degrees system =ΔH degrees system - TΔS degrees system ΔG degrees system = ?
What is a boundary layer inversion? Delimit top of surface mixed layer.
List four different types of pressure measurement devices. Manometer, bourdon tube gage, piezoelectric transducer, diaphragm
Thermal Equilibrium a state in which all parts of a system are at the same temperature
Conservation of energy principle or energy balance based on the first law of thermodynamics for closed systems may be expressed as follows: Energy can be neither created nor destroyed; it can only change forms. The net change (increase or decrease) in the total energy of the system during a process is equal to the difference between the total energy entering and the total energy leaving the system during that process. The energy balance can be written explicitly as
Change in energy (ΔE) ΔE = E(final) - E(initial) ΔE = E(products) - E(reactants)
What is the Kelvin temperature scale? It is more scientific, most equations use it- use same temperature unit size as Celcius. Freezing point is 273.15 K and boiling point is 373.15 K.
British Thermal Unit a unit of heat equal to the amount of heat required to raise one pound of water one degree Fahrenheit at one atmosphere pressure
Mass of a system is equal to the product of its molar mass M and the mole number N.
When/where/how will it differ from standard height? It will differ when g>go, g+go, and g<go. A meter is a set measurement that doesn't very with height and a geopotential meter is not a set measurement and is related to the height of the object, which can be small or large.
Thermal efficiency of a heat engine is the fraction of the thermal energy supplied to a heat engine that is converted to work.
What is another name for the first law of thermodynamics? The law of consevation of energy.
What is the ideal gas law for 100% relative humidity air look like and what environment is it used in? e=ρvRvT. This is used in an environment that is totally saturated, which means 100% relative humidity.