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Reference Guide

Permachart - Marketing Reference Guide: Carnot Heat Engine, Carnot Cycle, Isentropic Process

4 pages504 viewsFall 2015

Department
Chemistry
Course Code
CHEM 11100
Professor
All
Chapter
Permachart

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© 1998-2012 Mindsource Technologies Inc.
1PHYSICAL CHEMISTRY 1-55080-851-6
Basics
TM
permacharts
PHYSICAL CHEMISTRY
www.permacharts.com
Adiabatic
process
Process in which no heat is transferred into or out
of the system
Boiling point Lowest temperature at which liquid under fixed
pressure changes state from liquid to vapor
(vapor pressure = pressure on liquid)
Carnot cycle System undergoing a cyclical process involving
two reversible isothermal processes and two
reversible adiabatic processes
Carnot engine The most efficient heat engine which follows the
Carnot cycle
Chemical
potential (μ)
Measure of a chemical system’s tendency to
change (undergo a reaction, form a new phase)
Critical point Temperature where liquid and vapor are identical
Cyclical process A process which repeats a series of changes in the
system
Enthalpy (H)The quantity of heat in a substance per unit mass
under constant pressure
Entropy (S)A measure of degree of randomness of a system
Equilibrium state State in which state’s macroscopic properties
(such as temperature) are well defined and do
not change with time
Heat (q or Q)A form of energy; an energy transfer due to
temperature difference between system and
surroundings
Heat capacity (C)Total amount of heat needed to produce a one
degree rise in temperature of a given substance
Heat engine Device that converts heat into mechanical energy
Internal energy
(U or E)
The total kinetic and potential energy at the
molecular level
Irreversible process Non-equilibrium process in which no small change
in conditions could make the process go in reverse
Isobaric process Process in which pressure remains constant
Isochoric process Process in which volume remains constant
Isothermal process Process in which temperature remains constant
Mass Amount of matter in an object
Melting point The lowest temperature at which a solid under a
fixed pressure changes state from a solid to a liquid
Pressure (p or P)The force acting on a unit area
Quantity of heat Total kinetic energy of substance’s molecules
Reversible process Process whose direction may be reversed by
small change in one force; system is always
near equilibrium
State function
(state variables)
Property of system which has a definite value
for each state, and does not depend on how
the state is reached (such as temperature,
pressure, volume)
Temperature (T)Average kinetic energy of molecules of a substance
(Note: Not to be confused with quantity of heat)
Triple point Temperature and pressure at which 3 phases
of a substance (solid, liquid, vapor) co-exist in
equilibrium
Work (w or W)Form of energy transfer that may be represented
as a force acting through a distance
ENERGY CONVERSION FACTORS
PRESSURE CONVERSION FACTORS
TEMPERATURE CONVERSION FACTORS
CONSTANTS
1 J 1 Nm = 1kg m2/s2 = 0.239 cal = 107 erg = 2.78 x 10-7 kWh
= 9.481 x 10-4 Btu
1 cal 1.163 x 10-6 kWh =3.968 x 10-3 Btu = 4.186 x 107 erg
= 4.186 J
1 kWh 3.6 x 106 J = 8.601 x 105 cal = 3413 BTU = 3.6 x 1013 erg
1 BTU 1055 J = 252 cal = 2.93 x 10-4 kWh = 1.055 x 1010 erg
1 atm 1.01325 x 105 Pa = 1.01 x 105 N m-2 = 1.01325 bar
= 760 Torr = 760 mm Hg = 29.9 in Hg
1 Pa 9.869 x 10-6 atm = 7.5 x 10-4 cm Hg = 1 N m2
1 millibar 102 Pa
TF = 9/5 x TC + 32 TC = 5/9 (TF – 32)
TR = TF + 459.67 TK = TC + 273.15
F = Fahrenheit; C = Celsius; K = Kelvin; R = Rankine
Avogadro Constant (NA)6.0221367 x 1023 molecules/mol
Boltzmann Constant (k)1.380658 x 10-23J/K
Stefan-Boltzmann Constant (σ)5.67051 x 10-8 W/m2K4)
Molar Gas Constant (R) 8.314510 J/(mol K)
0.082058 (L atm)/ (mol K)
Molar Volume of an Ideal
Gas (Vm)
22.41410 L/mol (273.15 K, 1 atm)
eQUiliBriUm constants
• For reaction, aA bB cC dD
++
GAS EQUILIBRIUM
For gases, the equilibrium constant is
expressed in terms of partial pressures
CHEMICAL EQUILIBRIUM
At equilibrium, concentrations are
at a fixed ratio
At start of a reaction,
concentrations are at
a ratio
If QC < KC , then the reaction proceeds from
left to right
• If QC = KC , then the system is at equilibrium
If QC > KC , then the reaction proceeds from
right to left
ncdab=+−+()
()
where Δ
KCD
AB
C
cd
ab
equilibrium
=
[][]
[][]
QCD
AB
C
cd
ab
initial
=
[][]
[][]
K
PP
PP
p
C
c
D
d
A
a
B
b
=
[]
[][]
Kp = Kc (RT)Δn
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