WHAT IS THERMODYNAMIC PROCESSES / EXPLAIN ALL THE THERMODYNAMICS PROCESSES IN DETAIL

THERMODYNAMICS PROCESSES: BEFORE KNOWING THERMODYNAMICS PROCESSES  WE MUST HAVE THE KNOWLEDGE OF "WHAT IS THERMODYNAMICS " . THERMODYNAMICS IT IS SCIENCE OF ENERGY TRANSFER AND THE EFFECT OF THE TRANSFER ON THE PHYSICAL PROPERTIES OF SUBSTANCE SUCH AS PRESSURE,VOLUME,TEMPERATURE etc. WHEN A CHANGE IN THERMODYNAMIC STATE OF SYSTEM WE SAY THAT THE SYSTEM HAS UNDERGONE A PROCESS CALLED THERMODYNAMIC PROCESS. 
e.g the change take place inside the pressure cooker and heat engine.




















THE FOLLOWING ARE THE TYPES OF THERMODYNAMIC PROCESSES -

1.ADIABATIC PROCESSES: A PROCESS WHICH IS CARRIED OUT IN SUCH A WAY THAT THERE IS NO EXCHANGE OF HEAT BETWEEN SYSTEM AND SURROUNDINGS , IT IS CALLED ADIABATIC PROCESS .
HOWEVER ZERO HEAT TRANSFER IS AN IDEALIZATION, BUT A PROCESS IS APPROXIMATELY ADIABATIC IF THE SYSTEM IS WELL INSULATED OR IF THE PROCESS TAKES PLACE SO QUICKLY THAT THERE IS NOT ENOUGH TIME FOR APPRECIABLE HEAT FLOW TO OCCUR. IN SUCH PROCESSES, dq=0 .

2.ISOTHERMAL PROCESS: A PROCESS IN WHICH THE TEMPERATURE OF THE SYSTEM IS KEPT FIXED THROUGHOUT IS CALLED AN ISOTHERMAL PROCESS ALSO KNOWN AS CONSTANT- TEMPERATURE PROCESS. IN AN ISOTHERMAL PROCESS, TEMPERATURE IS KEPT CONSTANT BY ADDING OR REMOVING THE HEAT FROM THE SYSTEM. IN GENERAL, FOR AN ISOTHERMAL PROCESS NONE OF THE QUANTITIES W OR Q IS ZERO , BUT IN SOME SPECIAL CASES THE INTERNAL ENERGY OF A SYSTEM DEPENDS ONLY ON ITS TEMPERATURE, NOT ON ITS PRESSURE OR VOLUME. THE MOST COMMON SYSTEM FOLLOWING THIS SPECIAL CASE IS AN IDEAL GAS. FOR ISOTHERMAL PROCESSES  dT= 0

3. ISOBARIC PROCESS: IF A PROCESS IS CARRIED OUT AT CONSTANT PRESSURE , IT IS ISOBARIC PROCESS. IN ISOBARIC ONLY CHANGE OF VOLUME TAKES PLACE. FOR ISOBARIC PROCESSES, dP=0

LET US CONSIDER FORMATION OF WATER FROM HYDROGEN AND OXYGEN. THIS REACTION IS CARRIED OUT IN A VESSEL FILLED WITH AN AIR- TIGHT FRICTIONLESS PISTON, THE PISTON MOVE DOWNWARDS AS HYDROGEN AND OXYGEN REACTS TO FORM WATER. THIS REACTION PROCEEDS WITH DECREASE IN VOLUME. THIS DOWNWARD MOVEMENT OF PISTON MAINTAINS THE PRESSURE OF THE SYSTEM.

LET US CONSIDER DECOMPOSTION OF DINITROGEN TETRAOXIDE TO TWO MOLECULE OF NITROGEN DIOXIDE. THIS SYSTEM IS AGAIN FILLED WITH AN AIR- TIGHT FRICTIONLESS PISTON, THE PISTON MOVES UPWARDS AS DECOMPOSITION TAKES PLACE. THIS REACTION PROCEEDS WITH INCREASE IN VOLUME. THE UPWARD MOVEMENT OF PISTON MAINTAINS THE PRESSURE OF THE SYSTEM


4. ISOCHORIC PROCESS: IF A PROCESS WHICH IS CARRIED OUT AT CONSTANT VOLUME , IT IS ISOCHORIC PROCESS. IN AN ISOCHORIC PROCESS, CHANGE OF PRESSURE TAKES PLACE. IT IS ALSO KNOWN AS CONSTANT - VOLUME PROCESS. IN THIS PROCESS NO WORK IS DONE ON OR BY THE GAS , ALL THE ENERGY ADDED AS HEAT REMAINS IN THE SYSTEM AS AN INCREASE IN INTERNAL ENERGY AND ITS TEMPERATURE. THE CHANGE IN TEMPERATURE FOR A GIVEN AMOUNT OF HEAT IS DETERMINED BY THE SPECIFIC HEAT OF THE GAS AT CONSTANT VOLUME. FOR ISCHORIC PROCESSES , dV= 0

5. CYCLIC PROCESS: A PROCESS THAT EVENTUALLY RETURN A SYSTEM TO ITS INITIAL STATE IS CALLED A CYCLIC PROCESS. SINCE THE FINAL STATE IS THE SAME AS THE INITIAL STATE, AND SO THE TOTAL INTERNAL ENERGY CHANGES MUST BE ZERO BECAUSE INTERNAL ENERGY IS A STATE VARIABLE.

6. REVERSIBLE PROCESS: A PROCESS WHICH IS CARRIED OUT VERY- VERY SLOWLY AND OCCURS THROUGH SERIES OF STEPS IN SUCH A WAY THAT THE SYSTEM ALWAYS ALWAYS REMAINS IN A STATE OF EQUILIBRIUM. SUCH PROCESS CAN BE REVERSED AT ANY STAGE BY MAKING VERY SMALL CHANGE IN EXTERNAL CONDITION.

7. IRREVERSIBLE PROCESS: IF A PROCESS CAN GO IN ANY DIRECTION , IT IS IRREVERSIBLE PROCESS. IT DOES NOT TAKE PLACE SLOWLY. ALL NATURAL PROCESS ARE IRREVERSIBLE IN NATURE.




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