What is positive and negative deviation from Raoults law?

Answer: Raoults law states that the partial pressure of a component at any given temperature is equal to the mole fraction of that component in solution into the pure component vapour pressure.

p_i = p_i° × x_w

Here,

p_i = Partial pressure of component in valpour

p_i° = Partial pressure of pure component

x_w = Mole fraction in water.   

Positive and negative deviations are two different sorts of deviations that Raoult’s law .

Positive deviation occurs when the cohesiveness between like molecules weakens the adhesion between molecules that are unlike one another.

H_mixing > 0

Negative deviation: When the vapour pressure is lower than anticipated, a negative deviation occurs.

H_mixing< 0