What is meant by positive deviations from Raoult's law? Give an example. What is the sign of _mixH for positive deviation?

OR

Define azeotropes. What type of azeotrope is formed by positive deviation from Raoult's law? Give an example.

3.9 g of benzoic acid dissolved in 49 g of benzene shows a depression in freezing point of 1.62 K. Calculate the van't Hoff factor and predict the nature of solute (associated or dissociated).

(Given: Molar mass of benzoic acid = 122 g mol^-1, K_f for benzene = 4.9 K kg mol^-1

Calculate the mass of compound (molar mass = 256 g mol^-1) to be dissolved in 75 of benzene to lower its freezing point by 0.48 K (K_f= 5.12 kg mol^-1 )

Define an ideal solution and write one of its characteristics.

18 g of glucose, C₆H₁₂O₆ (Molar Mass = 180 g mol^-1) is dissolved in 1 kg of water in a saucepan. At what temperature will this solution boil? 

 (K_b for water = 0.52 K kg mol^-1, boiling point of pure water = 373.15 K)

250.

Determine the osmotic pressure of a solution prepared by dissolving 2.5 x 10^-2 g of K₂SO₄ in 2L of water at 25⁰C, assuming that it is completely dissociated. 

(R = 0.0821 L atm K^-1   mol^-1, Molar mass of K₂SO₄ = 174 g mol^-1)