Thermodynamics Test Flashcards

Terms Definitions
Adenosine Triphosphate
constant enthalpy
Plateau equation
q=m*(Heat constant)
Unit for energy
(see feedwater heater)
Prokaryote Cell Divison
Binary Fission
∆T=0, so ∆U=0 (process)
Relative density
(see specific gravity)
Natural convection
(see free convection)
Happens without effort; naturally; doesn't refer to speed of reaction (i.e. most exothermic and most combustion reactions); depends on specific perimeters
Subatomic Particles with neural charge, located in nucleus
energy into a system
is positive
driving force in spontaneous reactions
isothermal process
does not change temperature
Delta G = 0
At equilibrium
statistical mechanics
atomic and molecular theories...molecular interpretation of thermodynamics
Active site
business end, where substrates bind.
no energy transferred as heat (process)
Radiant Heat
heat energy transmitted by electromagnetic waves in contrast to heat transmitted by conduction or convection.
Open System
Mass flow across the boundaries
What is entropy?
Disorder, randomness or chaos.
Formal sign convention
(classical thermodynamics sign convention) for heat and work interactions is as follows: heat transfer to a system and work done by a system are positive; heat transfer from a system and work done on a system are negative.
the energy transferred between objects that are at different temperatures; energy is always transferred from higher-temperature objects to lower-temperature objects until thermal equilibrium is reached
Control Volume
Mass may cross the boundary
1st law
Energy is not created or destroyed
Food Calorie
1000 chemical calories (1kcal) = Cal
entropy formula
deltaS= sigma n S(products)-sigma n S(reactants)
energy transferred to or from system as work (variable)
potential energy
energy due to position or compostion
1000 calories; the energy required to raise the temperature of 1 kg H₂) by 1⁰C
Enthalpy Change
heat absorbed or released during chemical reactions
P-v-T surface
is a three-dimensional surface in space which represents the P-v-T behavior of a substance. All states along the path of a quasi-equilibrium process lie on the P-v-T surface since such a process must pass through equilibrium states. The single-phase regions appear as curved surfaces on the P-v-T surface, and the two-phase regions as surfaces perpendicular to the P-T plane.
is the process of removing moisture from atmospheric air.
Wet cooling tower
is essentially a semienclosed evaporative cooler.
holds system constant, such as the earth atmostpheric pressure
Measure of average kinetic energy of a substance
2nd Law
No system can operate at 100% efficiency
*We cant Get more energy than we start with
*Heat always flows from hot to cold
*Always lose some energy to heat transfer
Muti Enzyme Complexes
many enzymes working together,like an assembly line.
a system that can exchange energy but not matter with surroundings
energy absorbed or released as heat in a chemical or physical change is measured in this
process quantity
a property that depends on the specific transition (or path) between two equilibrium states.
% by volume
% by volume=(volume of solute)/(total volume of solution) x100%
where are there more molecules of gas in a reaction if S is positive
A mechanism of heat transfer in which cold (or hot) outside air infiltrates a heated (or cooled) building displacing heated (or cooled) air.
forms of energy are those related to the molecular structure of a system and the degree of the molecular activity, and they are independent of outside reference frames.
Exact differentials
are the differential changes for point functions (i.e., they depend on the state only, and not on how a system reaches that state), and they are designated by the symbol d. Properties are an example of point functions that have exact differentials.
Kinetic theory
treats molecules as tiny balls that are in motion and thus possess kinetic energy that allows heat to be defined as the energy associated with the random motion of atoms and molecules.
is a device based on the principle that an elevation change of Δz of a fluid corresponds to a pressure change of ΔP/ ρg, which suggests that a fluid column can be used to measure pressure differences. The manometer is commonly used to measure small and moderate pressure differences.
Dry air
is air that contains no water vapor.
If ΔH>0, a rxn is ___, or enthalpically ___
arrow of time
distinguishes the direction of time and exhibits time asymmetry
Free energy
the portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system.
Second law of thermodynamics
The principle whereby every energy transfer or transformation increases the entropy of the universe. Ordered forms of energy are at least partly converted to heat, and in spontaneous reactions, the free energy of the system also decreases. Spontaneous (natural) heat transfer always goes from hot to cold.
The C.O.P. of a heat pump is never less than 1. True or False.
specific heat
amount of heat required to raise the temp. of one gram of substance by 1 degree C or 1 K
The energy change (J) to convert 1KG of material from solid to liquid at same temperature
Latent heat
1 atmosphere and 25º C
standard pressure for reporting enthalpy changes
Saturated Liquid
A pure substance that exists as a liquid at saturation temperature and pressure
degrees of freedom
larger and more complex molecules have greater entropies
(= greater mass)
Entropy departure factor
is the nondimensionalized form of the entropy departure.
Compression-ignition (CI) engines
are reciprocating engines in which the combustion of the air-fuel mixture is self-ignited as a result of compressing the mixture above its self-ignition temperature.
Extensive properties
are those whose values depend on the size-or extent-of the system. Mass m, volume V, and total energy E are some examples of extensive properties.
Stoichiometric air
is the minimum amount of air, also called theoretical air, needed for the complete combustion of a fuel. When a fuel is completely burned with theoretical air, no uncombined oxygen will be present in the product gases.
Strong oblique shocks
are straight oblique shocks that have the larger possible values of the shock angles for deflection angles less than the maximum deflection angle.
Partial derivative
is the change in a function that depends on two (or more) variables, such as z = z (x, y), when allowing one variable to change while holding the others constant and observing the change in the function as another variable is held constant. The variation of z(x, y) with x when y is held constant is called the partial derivative of z with respect to x.
3rd law of thermodynamics
a pure crystalline substance at absolute zero temperature (0K or -273.15 degrees celsius) has a zero entropy

What is Boyle's Law?
At constant temperature, the volume of a given sample of gas varies inversely as pressure changes.
coefficient of performance
heat QL removed from the low-temp area inside a refrigerator divided by the work W to remove the heat
25 Joule Rule
states that the temperature of one mol of any solid metal or solid ionic compound is raised 1 °K when the metal absorbs 25 J of heat.
Specific Heat Capacity
Cp; the amount of energy needed to heat 1g of something by 1°C
Kinetic Energy
The energy of an object due to its mass and motion; calculated using the objects mass, m, and velocity, v.
Thermal energy reservoir
or just a reservoir is a hypothetical body with a relatively large thermal energy capacity (mass specific heat) that can supply or absorb finite amounts of heat without undergoing any change in temperature.
Heat of Formation
change in energy that takes place when one mole of a compound is formed from its component pure elements under standard state conditions
Hess's Law
The law that states that the amount of heat released or absorbed in a chemical reaction does not depend on the number of steps in the reaction
first law of thermodynamics
law saying energy of isolated system is constant despite any changes within the system
What is an isochoric process?
One in which volume doesn't change (dα=0).
What is a thermocouple thermometer? Explain its operational principle.
A thermocouple thermometer consists of two dissimilar metals that are joined together. The operational principle is based on the fact that an electromotive force will be developed for changes in temperature of the circuit.
Law of Conservation of Energy
energy cannot be created or destroyed, EVER
Conservation of mass principle
is expressed as net mass transfer to or from a system during a process equal to the net change (increase or decrease) in the total mass of the system during that process.
-, +
Where ΔH is + and TΔS is +, ΔG is _______at a high temperature and _________ at a low temperature
The Induced Fit
Lock & Key: only one type of key can fit.
Kelvin-Planck statement of the second law of thermodynamics
is expressed as follows: It is impossible for any device that operates on a cycle to receive heat from a single reservoir and produce a net amount of work. This statement can also be expressed as no heat engine can have a thermal efficiency of 100 percent, or as for a power plant to operate, the working fluid must exchange heat with the environment as well as the furnace.
what are the conditions like in a system near absolute zero?
we have superconductivity and superfluidity

According to Hess's Law, the entropy of a reaction
can be calculated from the standard entropies of the products and the reactants
Perpetual-motion machine of the second kind PMM2
is a device that violates the second law of thermodynamics.
What phases of water are in the air?
All three phases, vapor, liquid, and ice.
what happens as a system approaches absolute zero?
all processes cease and the entropy of the system approaches a minimum value
The molar heat capacity of a substance is the energy as heat needed to
raise the temperature of one mole by 1 K
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