16. Critical Volume: The volume of 1 mole of gat at Tc, Pc.
17. Super cooled liquids: The liquids which are cooled to a temperature below its freezing point without freezing.
18. Elastic Collision: The collisions in which no loss of K. E. only there is transfer of energy.
19. Vapour pressure: The equilibrium pressure by vapour of liquid in a container at given temperature( T)
20. At higher altitude: The b. p. of water decreases b / c the atmospheric pressure is less than one atmosphere.
21. Surface Tension( V): It is force acting per unit length Perpendicular to the line drawn on the surface:( Nm-1): It decreases with increases in T, it increases with increase in external pressure, b / c of it falling drops of liquid are spherical, liquid in capillary tube rises.
22. Viscosity( η): It is resistance offered to the flow of liquid due to friction b / w layer of fluids. F n. A. dn dv
23. Effect of T & P on viscosity: It decreases with increase in T, and increases with increase in P.
24. Low M. P. & B. P. of molecular liquids is due to low magnitude of molecular interaction energy.