Define immiscible liquid.

Liquids does not mix with each other and form a separate layer.

liquids are said to be immiscible if they're completely insoluble in each other. Such a system actually consists of 2 phases, though it is usually referred to as a mixture. Examples include benzene and water, kerosene and water, etc. Though classified as immiscible, in actual fact, there is still some degree of mutual solubility. For example, again using the example of benzene and water, a small amount of benzene will be dissolved in the water phase, and vice versa. Since by definition, immiscible liquids do not interact with each other in any way whatsoever, they will evaporate completely independent of each other. In other words, each liquid will contribute its own characteristic equilibrium vapour pressure regardless of the presence of the other liquid. Thus, the total pressure exerted by the mixture is the sum of the equilibrium vapour pressures. For example, the 2 liquids A and B are immiscible. At equilibrium, they each exerts equilibrium vapour pressure PVP,A and PVP,B respectively. Thus the total pressure exerted is P = PVP,A + PVP,B

Immiscible liquids :

The liquids which form a separate layer and does not mix with another liquid are called immiscible liquids.

Examples -

Oil and Water

The classic example of immiscible liquids is oil and water. Water is very polar; the positive hydrogen end of the molecule forms especially strong hydrogen bonds with the negative oxygen end of another water molecule. Oil in this example can be any liquid fat or even motor oil. Oil is a non-polar molecule, so when you put the two liquids together, they do not mix. In addition to enthalpy, water is a special case where entropy also prevents mixing in what is known as the hydrophobic effect.