State the following:

(i) Raoult’s law in its general form in reference to solutions.

(ii) Henry’s law about partial pressure of a gas in a mixture.

(i)

(a) Raoult’s law states that in a solution having two or more miscible volatile liquids, partial vapour pressure of each component of the solution at a given temperature is directly proportional to its mole fraction.

Let there be 2 liquids a and b.

P = (P_a x_a) + (P_b x_b)

Where, P is total vapour pressure of the solution.

P_a and P_b are the vapour pressure of components a and b.

X_a and x_b are the mole fractions of components a and b.

(ii)

Henry’s law states that the partial pressure of gas in vapour phase (p) is directly proportional to the mole fraction of gas (x) in the solution. It is expressed as:-

P = K_Hx

Here, K_H is Henry’s constant.