„ Heat is energy in transit which flows from hot object to cold object. However it is not a quantity.

„ Work is a process to transfer energy from one object to another object.

„ Temperature is a measure of hotness of the object. It determines the direction of the flow of heat.

„ The ideal gas law is PV = NkT or PV = μRT. The Ideal gas law holds for only at thermodynamic equilibrium. For non-equilibrium process, it is not valid.

„ Heat capacity is the amount of heat energy required to increase the object’s temperature by 1°C or 1K. It is denoted by S.

„ Specific heat capacity is the amount of heat energy required to increase the 1 kg of object’s temperature by 1°C or 1K. It is denoted by s.

„ Molar specific heat capacity is the amount of heat energy requires to increase the 1 mole of substance’s temperature by 1°C or 1K. It is denoted by C.

„ Thermal expansion is a tendency of an object to change its shape, area, and volume due to change in temperature.

„ Water has an anomalous behavior of expansion.

„ Latent heat capacity is the amount of heat energy required to change the phase of the substance.

„ Calorimetry is the measurement of the amount of heat energy released or absorbed by thermodynamic system during the heating process.

„ Heat transfers in three different modes: conduction, convection and radiation

„ Stefan-Boltmann law: E = σ T4 and Wien’s law: λmax T = b

„ Thermodynamic equilibrium: thermal, mechanical and chemical equilibrium

„ Thermodynamic variables : Pressure, temperature, volume, internal energy and entropy

„ Zeroth law of thermodynamics: If two objects are separately in thermal equilibrium with the third object, then these two are in thermal equilibrium. Temperature is a property which is the same for both the systems.

„ Internal energy is the sum of kinetic and potential energies of molecules in the thermodynamic system.

„ Joule converted mechanical energy to internal energy of the thermodynamic system

„ First law of thermodynamics is a statement of conservation of energy. It included heat energy of the thermodynamic system.

„ A quasi-static process is an infinitely slow process in which the system is always at equilibrium with the surrounding.

„ When the volume of the system changes, the work done W = ∫P dV

„ The area under the PV diagram gives the work done by the system or work done on the system.

„ Specific heat capacity at constant volume is always less than specific heat capacity at constant pressure.

„ Isothermal process: T = constant, Isobaric process: P=constant, Isochoric process: V= constant, Adiabatic process Q = 0

„ Work done in the isobaric process is most and work done in the adiabatic process is least

„ In a cyclic process, change in internal energy is zero.

„ The total work done in the cyclic process is given by a closed area in PV diagram

„ A reversible process is an ideal process.

„ All natural processes are irreversible.

„ Heat engine takes input from the hot reservoir, performs work and rejects some amount of heat energy into sink.

„ Carnot engine is a reversible engine. It has the highest efficiency. No real heat engine can have the efficiency of that of a Carnot engine.

„ A refrigerator is reverse of a Carnot engine. COP (coefficient of performance) of the practical refrigerator is always less than ideal refrigerator