1. BSC. -II PHYSICAL CHEMISTRY THERMODYNAMICS-II

2. THERMODYNAMICS -II

3. LIMITATION OF FIRST LAW OF THERMODYNAMICS • It does not give information concerning feasibility of a thermodynamic process. why NOT EXPLAINED BY FIRST LAW

4. It tells that work obtained is equal to heat absorbed but in actual heat absorbed can not be completely converted into work. Limitations motivating second law

5. It will arouse changes while the heat transfers from low temp.substance to high temp. one. The second law of thermodynamics

6. DIFFERENT STATEMENTS OF SECOND LAW • All spontaneous processes are thermodynamically irreversible. • .

7. The complete conversion of heat into work is impossible without leaving its effects somewhere. SOME AMOUNT OF HEAT MOVES TO SURROUNDING

8. Without the use of any external agency ,heat can not by itself pass from a colder body to a hotter body EXTERNAL AGENCY HEAT TRANSFER HOT BODY COLD BODY

9. Carnot cycle and its efficiency Sadi Carnot devised a technique, called Carnot Cycle. Carnot chose a reversible heat engine ,.known as carnot engine, consisting of one mole of ideal gas , fitted with frictionless piston ,insulated on all sides except bottom. This engine is having 2 heat reservoirs , one at higher temperature T2 and the other at a lower temperature T1. The Carnot Cycle consists of 4 different operations: Isothermal expansion Adiabetic expansion Isothermal compression Adiabetic compression

11. ISOTHERMAL(T2) I ADIABETIC IV II ADIABETIC III PRESSURE ISOTHERMAL(T1) VOLUME

12. Carncarnot cycle w1= -RT2ln(V2/V1) q2=-w State 1 T2 State 2 T2 isothermal q=0, W4=CvT q=0, w2=-CVT adiabatic adiabatic isothermal State 4 T1 State 3 T1 w3= RT1ln(V4/V3) -q1=w3