Thermodynamics Chapter 1 Hacktheview

Front 1

Macroscopic

Back 1

-system is analyzed with reference to its molecular structure or molecular behaviour

Front 2

Microscopic

Back 2

-system is analyzed with reference to its molecular structure or molecular behaviour

Front 3

Microscopic vs Macroscopic

Back 3

Large number of variables | LessTime consuming calculations | faster and simpleStatistical thermodynaics by pure scientist | applied thermodynamics by engineers

Front 4

Closed System

Back 4

System in which energy transfer can take place but mass cannot.. Eg : Ideal gas contained in a piston cylinder. Total mass of closed system is always constant. so called Control Mass

Front 5

Open System

Back 5

System in which both mass and energy can take place. eg : air compresser, also called controlled volume

Front 6

Isolated System

Back 6

system in which neither mass nor energy can take place. Eg : Closed Rigid isolated box

Front 7

Thermodynamic property

Back 7

Any variable or parameter used to describe thermodynaic system. divided into intensive and extensive properties

Front 8

Intensive property

Back 8

Thermodynamic property which is independent of mass or part of system considered. Eg. pressure, temperature

Front 9

Extensive property

Back 9

Thermodynamic property which is dependent upon the mass or part of the system. Eg : entropy, enthalpy, volume.

Front 10

Extensive to Intensive

Back 10

Since extensive properties are proportional to mass, they can be converted into intensive by dividing them by mass.e = E/me = Specific energy (usually denoted by small letters)E = Total Energy(usually denoted by capital letters)m = Mass

Front 11

Thermodynamic Equilibrium

Back 11

If there is no change in any properties of the system when it is isolated from its surroundings.If all intensive properties have same value throughout the systemIf there is no change in any properties of the system when it is isolated from its surroundings.If all intensive properties have same value throughout the system

Front 12

Condition for thermodynamic system to be in equilibrium

Back 12

Thermal equilibrium, chemical equilibrium, mechanical equilibrium:

Thermal equilibrium : There should be no temperature difference within the system

Chemical equilibrium : There should be no chemical reaction during observation interval

Mechanical equiliubrium : There shouldn't be any pressure difference or unbalanced force/moment within the system.

Front 13

Thermodynamic state

Back 13

Each unique condition at which a thermodynamic system can exist is thermodynamic state. It is specified with the values of thermodynamic properties.

eg : State 1 at T1 = 25 C P1=1 Pa , State 2 at T2=50 P2 = 2Pa

Constant property and Variable property

Front 14

State functions

Back 14

All thermodynamics properties depend only on the end states and they are called state functions.

Front 15

Path functions

Back 15

Variables such as work and heat depend not only on the end states but also on the path and are called path fuctions.

Front 16

Thermodynamic process

Back 16

The path followed by system when it undergoes from one equilibrium state to another is called thermodynamic process.

Thermodynamic process is defined with the help of property diagrams such as P-V, T-V, P-T, h-s, T-s , P-h diagrams etc.

Front 17

Reversible process

Back 17

Any process which passes through a series of equilibrium states such that each intermediate state can be located on a property diagram is called reversible process.

Front 18

Irreversible process

Back 18

Any process which passes through a series of intermediate states which can not be defined or cannot be located on property diagram is called an irreversible process. Represented by broken line

Front 19

Reversible/Irreversible Example

Back 19

Take two piston-cylinder device, one with a huge block and other with number of small blocks. Removing from first block one by one and adding again is reversible process but adding big block and removing is not reversible process.

Front 20

Pressure

Back 20

Pressure exerted by ambient air on any surface is called atmospheric pressure.

Pressure of any system measured with reference to atmospheric pressure is called gauge pressure.

Pressure of system expressed relative to perfect vacuum is called absolute pressure.

Pabs = Patm + Pgauge

Front 21

Zeroth law of thermodynamics

Back 21

Consider three systems A,B and C. A-C contact same temperature, B-C contact same temperaturem then A-B will be same temperatue without testing.