THERMODYNAMICS Flashcards
what is initial point of Celsius scale
0 degree
Example: Freezing point of water
molar specific heat capacity for isobaric process
Cp
what is thermodynamics
conversion of heat energy into other forms of energy
the internal energy of ideal diatomic or polyatomic gas is equal to
translational kinetic energy + rotational kinetic energy + vibrational kinetic energy + potential energy
Formula: U = K.E trans + K.E rot. + K.E vib. + P.E
1st law of thermodynamics is another form of
law of conservation of energy
no. of divisions in celcius scale
100
example of isothermal process
boiling of water once it reaches 100 degree celcius
temperature scale tables
rows: initial point, final point, divisions
columns: C, F, K
Draw it
does adiabatic process obey Boyle’s law
no
change in internal energy does not depend upon
path followed
in isothermal process, △T is
zero
example of isochoric process
pressure cooker
what is thermodynamic system
the set of particles having certain values of pressure, volume and temperature
molar specific heat capacity for isochoric process
Cv
molar specific heat capacity C for isothermal process
infinity
what is isobaric process
it is a process in which pressure remains constant
no. of divisions in kelvin scale
100
value of γ(gamma) for monoatomic gas is
1.69
value of molar specific heat capacity C for adiabatic process
zero
PV graph for adiabatic process is
steep curve
what is final point of celcius scale
100 degree
when will the work done be positive
when done by system
PVγ is constant for
adiabatic process
according to indicator diagram for expansion, which process does most work
isobaric
work done in isochoric process is
zero
Kinetic Molecular Theory (KMT) is likely to break at
high pressure, low temperature
final point of fahrenheit scale
212 degree
order of work done by each process for compression is
adiabatic > isothermal > isobaric
in adiabatic process, △Q is
zero
what is temperature
the degree of hotness or coldness of a body
when will be the change in heat supplied be positive
when heat is absorbed
formula for internal energy of gases
U = K.E trans + K.E rot. + K.E vib. + P.E
Formula: U = K.E trans + K.E rot. + K.E vib. + P.E
for isothermal process, △Q is equal to
W
according to indicator diagram for compression, which process does most work
adiabatic
the internal energy of monoatomic gas is equal to
translational kinetic energy
Formula: U = K.E trans
when will the work done be negative
when done on system
The 1st law of thermodynamics states that
heat supplied to a system is always equal to the change in internal energy plus the work done on the surroundings
in isothermal process, which values remain constant
temperature and internal energy
what is the initial point of temperature scales
freezing point of water
what is adiabatic process
the process in which no heat enters or leaves the system
what is thermodynamic process
any change in pressure, temperature and volume
what is isothermal process
the process in which temperature remains constant
PV graph for isochoric process is
straight line parallel to y-axis
what is state function
values that only depend on initial and final points, not the path followed
initial point of kelvin scale
273
example of adiabatic process
sound propagation
cloud formation
rapid escape of air from burst tyre
shaking of hot air in thermoflask
PV graph for isobaric process is
straight line parallel to x-axis
formula for first law of thermodynamics
△Q = △U + W
Formula: △Q = △U + W
1st law of thermodynamics for isobaric process
△Qp = △U + W
no. of divisions in fahrenheit scale
180
area under PV-graph gives value of
work done
which of the following is smallest? 1C, 1F, 1K
1F
according to indicator diagram for expansion, which process does least work
adiabatic
in thermodynamic cyclic process, change in internal energy is
zero
when will the change in internal energy be negative
when energy decreases
in adiabatic process, W is equal to
-△U
what is isochoric process
it is a process in which volume remains constant
final point of kelvin scale
373
what is final point of temperature scales
boiling point of water
which of the following is lowest? 1C, 1F, 1K
1K
what is internal energy?
the sum of all types of energies possessed by gas molecules
write the 7 state functions
pressure
temperature
volume
internal energy
enthalpy
entropy
Gibbs free energy
when will the change in internal energy be positive
when energy increases
when will the change in heat supplied be negative
when heat is released
internal energy is __________ function
state
what is isolated system
a system in which both mass and heat cannot be exchanged with the surroundings
relation of Cp and Cv is
Cp - Cv = R
the PV graph of isothermal process is
a curve
what is close system
a system in which mass cannot be exchanged but heat can
What is enthalpy?
Enthalpy is a state function.
State
What is entropy?
Entropy is a state function.
State
What is Gibbs free energy?
Gibbs free energy is a state function.
State
When will the change in internal energy be positive?
When energy increases.
When energy increases
When will the change in heat supplied be negative?
When heat is released.
When heat is released
Internal energy is a ______ function.
Internal energy is a state function.
State
What is an isolated system?
A system in which both mass and heat cannot be exchanged with the surroundings.
A system in which both mass and heat cannot be exchanged with the surroundings
What is the relation of Cp and Cv?
Cp - Cv = R.
Cp - Cv = R
The PV graph of an isothermal process is what shape?
The PV graph of an isothermal process is a curve.
A curve
What is a closed system?
A system in which mass cannot be exchanged but heat can be exchanged with the surroundings.
A system in which mass cannot be exchanged but heat can be exchanged with the surroundings
Give an example of an isobaric process.
Cooking of food with an open lid.
Cooking of food with an open lid
How is internal energy a state function?
Because it only depends upon the initial and final values, regardless of the path taken.
Because it only depends upon the initial and final values, regardless of the path taken
What is an open system?
A system in which both mass and heat can be exchanged with the surroundings.
A system in which both mass and heat can be exchanged with the surroundings
What is the value of γ for a polyatomic gas?
1.29.
1.29
What is the 1st law of thermodynamics for an isochoric process?
ΔQ = ΔU.
ΔQ = ΔU
What law does an isothermal process obey?
Boyle’s law.
Boyle’s law
What is the order of work done by each process for expansion?
Isobaric > Isothermal > Adiabatic.
Isobaric > Isothermal > Adiabatic
What is the formula for temperature conversions?
Scale-initial point/divisions = scale-initial point/divisions.
Scale-initial point/divisions = scale-initial point/divisions
What is the value of γ for a diatomic gas?
1.40.
1.40
In an isothermal process, what is ΔU?
Zero.
Zero
What is a state function also known as?
State variable.
State variable
Which temperature scale is most sensitive?
Fahrenheit.
F
At which temperature do Celsius and Fahrenheit become equal?
40 degrees.
40 degrees
What is the initial point of the Fahrenheit scale?
32
According to the indicator diagram for compression, which process does the least work?
Isobaric.
Isobaric
What is the formula for γ (gamma)?
Cp/Cv.
Cp/Cv
What is the work done of a thermodynamic cyclic process?
Not zero.
Not zero
In an isothermal process, what is PV?
Constant.
Constant
for an ideal gas, the potential energy of gas molecules is
zero
which law gives concept of temperature?
zeroth law of thermodynamics
what is the unit for specific heat capacity?
J / K kg
a point on PV diagram represents
state or condition of the system
the relation between work and heat of a system is
direct
out of solid, liquid and gas of same mass and at same temperature, which one has highest internal energy?
gas
in isothermal expansion, the pressure is determined by
compressibility only
a thermodynamic system is changed from state (P1V1) to (P2V2) by two different processes. the quantity which will remain same will be
△Q - △H
the area under a PV diagram represents
work done on or by the system
the curve which represents an isothermal process is called
isotherm
why is water used as a coolant in automobiles?
because it has a high heat capacity
when two bodies are said to be in thermal equilibrium, the net heat exchange between them is
zero
heat is not being exchanged with a body. if its internal energy is increased then the temperature will
increase
a curve drawn between two points on PV diagram represents
a thermodynamic process
