1. LECTURE 3 CHAPTER 11 HEAT

2. EQUPMENTS REQUIRED BEFORE START OF LECTURE
BOOK (WITH THE PARTICULAR CHAPTER OPENED)
ROUGH REGISTER
PEN & CALCULATOR

3. TOPICS TO BE COVERED Heat Capacity
Latent Heat
Latent Heat of Capacity
Specific Heat Capacity
Molar Specific Heat Capacity (Derivation)
Prove Cp - Cv = R (Derivation)
Thermodynamics
First Law of Thermodynamics (Explanation)

4. Heat Capacity: All substances naturally posses ability to absorbing some heat. This natural ability of substances is called Heat Capacity.
Latent Heat : Latent heat of a substance is defined as the amount of heat required to change the state of the unit mass of a substance
H = ∆Q/m
S.I unit is J/Kg

5. There are two types of Latent Heat
Latent Heat of Fusion: It is the amount of heat required to melt the unit mass of a solid
Hf = ∆Q/m
Latent Heat of Vaporization: It is the amount of heat required to vaporize the unit mass of a liquid.
Hv = ∆Q/m

6. Specific Heat Capacity: The amount of heat required to rise the unit mass of a substance through one Kelvin or one degree Celsius.
C= ∆Q/m∆T
S.I unit is J/Kg-1K-1

7. Molar Specific Heat Capacity at Constant Pressure & Volume is equal to Universal Gas Constant
Cp - Cv = R

8. First Law of Thermodynamics
Thermodynamics: The branch of physics that deals with the transformation of heat energy into mechanical energy
First Law of Thermodynamics
“When heat is transformed into mechanical energy or when other mechanical energy is transformed into heat energy the total amount of energy remains constant”
∆Q = ∆U + ∆W

9. Sign Convention
∆Q is taken positive when heat enters the system and negative when heat leaves the system
∆W is taken positive when work is done by the system and negative when work is done on the system
∆U is taken positive when internal energy of the system increases and taken negative when decreases

10. Isolated System: An isolated system is the one which has no surroundings, that is there is no flow of heat in or out from the system and hence the system is not capable to do work.
Cyclic Process: A cyclic process is the one which starts and ends up at the same state i.e. system finally attains its initial state.