Units. Thermodynamic system and surroundings. Working body. Properties of state. Equilibrium, change of state, process. The zero law of thermodynamics. Ideal gas law. Conservation of energy. The concept of energy. Internal energy. Enthalpy. Heat capacity. Mayer's equation. The first law of thermodynamics for a closed and open thermodynamic system. p-v diagram, work, and thermodynamic process in p-v diagram. The second law of thermodynamics. Reversible, irreversible and imposible process. Thermodynamic cycle. Properties of state for a thermodynamic cycle. Cloclkwise thermodynamic cycle. Carnot cycle. Thermal efficiency. The concept of entropy. The mathematical expression of the second principle of thermodynamics. Enthropy change of ideal gases. Heat, T-s diagram, and thermodynamic process in T-s diagram. Counter-clockwise cycles. Entropy change of a thermodynamic system. The second principle of thermodynamics for a cycle. Entropy change of an isolated thermodynamic cycle. The third principle of thermodynamics.