Raoult’s law class 12

Define raoult's law

Raoult's law:- A solution of volatile liquids the partial vapour pressure of each component in the solution is directly proportional to it's mole fraction for liquid 1 and liquid 2.

Partial pressure for liquid 1

p₁ α n₁

p₁ = p_i1n_{1 ---(1)}

Partial pressure for liquid 2

p₂ α n₂

p₂ = p_i2n_{2 ---(2)}

What does raoult's law state ?

Raoult's law state that total pressure over solution phase in the container will be the sum of the partial pressure of components of the solution.

p_total = p₁ + p₂

p_total = p_i1n₁ + p_i2n2

p_total = (1-n₂)p_i1+ p_i2n2                                                  ∴ (n_{1 +} n2 =1)

p_total = p_i1 - p_i1n2 + p_i2n2

p_total = p_i1 + (p_i2 - p_i1)n2

Raoult's law formula :- p_total = p_i1 + (p_i2 - p_i1)n2