Is the expression for work of a polytropic process restricted to processes of an ideal gas?

Is the expression for work of a polytropic process restricted to processes of an ideal gas?

The specific heats will be discussed later. Notice that the results we obtained for an ideal gas undergoing a polytropic process when n = 1, is identical to that for an ideal gas undergoing the isothermal process….The Polytropic Process:

Process	Exponent n
Isothermal & ideal gas	1
Adiabatic & ideal gas	k = CP/CV

What is a polytropic process used for?

The polytropic process can describe gas expansion and compression which include heat transfer. The exponent n is known as the polytropic index and it may take on any value from 0 to ∞, depending on the particular process.

What does a polytropic process mean?

A polytropic process is a thermodynamic process that obeys the relation: where p is the pressure, V is volume, n is the polytropic index, and C is a constant. The polytropic process equation can describe multiple expansion and compression processes which include heat transfer.

What is work done in adiabatic process?

When an ideal gas is compressed adiabatically (Q=0), work is done on it and its temperature increases; in an adiabatic expansion, the gas does work and its temperature drops.

In which process work done is zero?

isochoric process

In which process work done is maximum?

The maximum work is done when the external pressure Pext of the surroundings on the system is equal to P, the pressure of the system. If V is the volume of the system, the work performed as the system moves from state 1 to 2 during an isobaric thermodynamic process, W12, is the maximum work as given by Eq.

Which work done is more adiabatic or isothermal?

In the isothermal process, the heat is given by surrounding for work done whereas the heat change is zero in the adiabatic process so, the work done in the isothermal process is greater than the work done in the adiabatic process.

Does isothermal mean adiabatic?

In thermodynamics, an isothermal process is a type of thermodynamic process in which the temperature of the system remains constant: ΔT = 0. In contrast, an adiabatic process is where a system exchanges no heat with its surroundings (Q = 0).

Can a process be both adiabatic and isothermal?

The gas reacts (chemically), releasing energy in the process until a new equilibrium is established at the original temperature. Thus, the whole process would be both adiabatic and isothermal.

Why isothermal process is not possible?

Ans. In isothermal process, temperature of the system is constant and also equal to that of surroundings in contact with the system. Heat supplied to a system is possible if there is some temperature difference between the system and surrounding. Hence, isothermal process is not possible practically.

Is adiabatic process reversible?

It is an idealized thermodynamic process that is adiabatic and in which the work transfers of the system are frictionless; there is no transfer of heat or of matter and the process is reversible.

What is an example of an isothermal process?

Examples of Isothermal Process Changes of state or phase changes of different liquids through the process of melting and evaporation are examples of the isothermal process. A refrigerator works isothermally. A set of changes take place in the mechanism of a refrigerator but the temperature inside remains constant.

Is there heat transfer in isothermal process?

An isothermal process is any process in which the temperature of the system remains constant. According to the First Law of Thermodynamics, the change in internal energy of a closed system is equal to the heat transferred into the system plus the work done by the system.

Does isothermal mean no heat transfer?

The temperature change in an isothermal process is zero. As a result (if the system is made of an ideal gas) the change in internal energy must also be zero.

Why is CP is greater than CV?

Cp is greater than the molar specific heat at constant volume Cv because energy must now be supplied not only to raise the temperature of the gas but also for the gas to do work. It follows therefore that the temperature rise at constant pressure will be less for a given quantity of heat transferred.

How do you calculate isothermal process?

A curve in a P-V diagram generated by the equation PV = const is called an isotherm. For an isothermal, reversible process, the work done by the gas is equal to the area under the relevant pressure -volume isotherm. It is given as WA→B=NkTlnVBVA W A → B = NkT ln ⁡ V B V A .

How do you do isothermal compression?

The isothermal approach is used to enhance the heat transfer of compressed air to maintain the temperature constant as the environment. Two main methods to achieve isothermal compression are to inject the liquid spray or foam into the compression chamber and liquid piston.

What are the limitations of the first law of thermodynamics?

The limitation of the first law of thermodynamics is that it does not say anything about the direction of flow of heat. It does not say anything whether the process is a spontaneous process or not. The reverse process is not possible. In actual practice, the heat doesn’t convert completely into work.

What is r in PV nRT?

In the equation PV=nRT, the term “R” stands for the universal gas constant. The universal gas constant is a constant of proportionality that relates the energy of a sample of gas to the temperature and molarity of the gas.

What is PV is equal to nRT?

PV=nRT. The ideal gas Law PV = nRT. Robert Boyle found PV = a constant. That is, the product of the pressure of a gas times the volume of a gas is a constant for a given sample of gas. In Boyle’s experiments the Temperature (T) did not change, nor did the number of moles (n) of gas present.

What units are used in PV nRT?

In SI units, p is measured in pascals, V is measured in cubic metres, n is measured in moles, and T in kelvins (the Kelvin scale is a shifted Celsius scale, where 0.00 K = −273.15 °C, the lowest possible temperature). R has the value 8.314 J/(K.

Can you use mmHg in PV nRT?

Note the different value and unit for R, to be in agreement with using mmHg for the pressure unit. Alternatively, you could convert 780. mmHg to atm and then use 0.08206 L atm / mol K for the value of R. A variety of values for R can be found here.

What is the ideal gas law used for?

Determining Gas Volumes in Chemical Reactions. The ideal gas law can be used to calculate volume of gases consumed or produced. The ideal-gas equation frequently is used to interconvert between volumes and molar amounts in chemical equations. Begin by converting the mass of calcium carbonate to moles.

What is the value of R in the ideal gas law?

8.314 J/mol

How do you calculate ideal gas?

Boundless Chemistry

1. The ideal gas equation is given by PV=nRT P V = n R T .
2. PV=nRT.
3. 8.3145L⋅kPaK⋅mol=0.0821L⋅atmK⋅mol=62.4L⋅mm HgK⋅mol.