Question

define saturated Vapour pressure of liquid how does it vary with temperature

Answer 1

As the temperature rises, the saturated vapour pressure increases rapidly, and so does the density of the vapour, approaching that of the liquid. At a certain temperature the density of the vapour becomes equal to that of the liquid, and the vapour and liquid become indistinguishable. In other words, the equilibrium curve of the liquid and gas in the pT phase diagram terminates at some point (K in Fig. 85). This is called the critical point, and its coordinates are called the critical temperature Tc and critical pressure pc of the substance.