Midterm 1 Flashcards
What is the equation for Linear Thermal Expansion?
ΔL = α L(0) ΔT
ΔL = Change in Length
L(0) = Original Temperature
α = Coefficeint of Linear Expansion
ΔT = Change in Temperature
What is the equation for Volume Thermal Expansion?
ΔV = β V(0) ΔT
ΔV = Change in Volume
V(0) = Original Volume
β= Coefficeint of Volume Expansion
ΔT = Change in Temperature
What is meant by an equation of state?
A mathematical relation between variables in a thermodynamic system.
What are the equations of state for an ideal gas?
P V = n R T = N k(b) T
P = Pressure
V = Volume
n = Number of moles
N = Number of atoms
R = Gas constant
k(b) = Boltzman Constant
T = Temperature
What is Boyle’s Law?
P ∝ 1/V
Constant n and T
What is Charles’ Law?
V ∝ T
Constant n and P
What is Avagadro’s Law?
V ∝ n
Constant P and T
What is meant by Isotherm?
Path with constant temperature
What is meant by Isobar?
Path with constant pressure
What is meant by Isochoric?
Path with constant volume
When is the ideal gas equation valid?
When:
No interparticle reactions.
Particle velocities are non-relativistic.
Interparticle distance is greater than compton wave length.
High Temp
Low presssure
What is trhe Van der wall equation of state?
(P + (an)/V²) ( V- Nb) = nRT
nb = Volume of particle
an/V² = Interparticle Reaction
What is the Virial equation of state?
(PV)/(nRT) = 1 + B(1) (n/V) + B(2) (n/V)² ….
What is STP?
Standard Room Temperature and Pressure.
0°C = 273.15K
1 bar = 100kPa
What is RTP?
Room Temperature and Pressure.
25°C = 298.15K
101kPa
What is 1cal equivalent to?
1 cal = 4.186J
1 Kcal = 4186J
What is the equation for Specific Heat Capacity?
Q = m c ΔT
Q = heat required to change temp of a certain mass.
m = mass
c = specific heat capacity
ΔT = Change in temp
What is the equation for infintesimally small changes in temp for Specific Heat Capacity?
dQ = m c dt
What is the equation for Conduction Heat Transfer?
H = dQ/dt = K A (Th - Tc)/L
H = heat current (W)
K = Thermal conductivity of Material
A = Cross sectional area
Th = Hotter temp
Tc = Colder temp
L = length of rod
What is the equation for Thermal Resistance?
Rth = L/(KA)
H = Rth (T2-T1)
Rth = Thermal Resistance (K W^-1)
K = Thermal Resitance
A = Cross sectional area
What is the equation for Heat Transfer through Radiation?
H = A e σ T^4
H = Heat Transfer
A = Surface area
e = emistivity (0 ideal reflector –> 1 ideal absorber)
σ = Stefan Boltzmann constant
T = Temperature
what is the equation for Thermal Energy of an Ideal gas?
U = 3/2 N k(b) T = 3/2 n R T
U = Energy
N = Number of atoms
n = Number of moles
k(b) = Boltzmann Constant
R = Gas constant
T = Temperature
What is the equation for the RMS velocity?
v(RMS) = ((3 k(b) T)/m)^0.5 = ((3 R T)/M)^0.5
v(RMS) = Root mean square velocity
k(b) = Boltzmann constant
T = Temperature
m = Mass
M = Molecular mass
R = Gas constant
What is the equation for the Average Kinetic Energy of a Gas Molecule for an ideal gas?`
1/2 m <v²> = 3/2 k(b) T
m = mass
<v²> = Average squared Velocity
k(b) = Boltmann constant
T = Temperature
What is Heat Capacity per mole of a Monatomic Ideal gas?
3R/2 = Cv = 12.47 J K^-1 mol^-1
R = Gas constant
Cv = Amount of heat absorbed / emitted per unit of a substance at constant volume
What is the Heat Capacity per mole of a Diatomic Ideal gas?
5R/2 = Cv = 20.79 J K^-1 mol^-1
R = Gas constant
Cv = Amount of heat absorbed / emitted per unit of a substance at constant volume
What is the Heat Capacity of an Ideal Gas?
U = 1/2 v N k(b) T = 1/2 v n R T
U = Energy
v = degrees of freedom
N = Number of atoms
k(b) = Boltzmaan constant
T = Temperature
n = Number of moles
R = Gas constant
