Azeotropes
Properties of solution affected by vapour pressure
Azeotropes
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Azeotropes are binary mixturespossessing the same synthesis in fluid, vapor stage and boiling stage at a steady temperature.
The components of azeotropic mixtures are separated by fractional distillation.
Azeotropes can be broadly categorized into two types- 1. Minimum boiling azeotrope
The solutions showing positive deviation from Raoult’ s law. For instance, solution of ethanol and water on fractional distillation results in a solution containing approximately 95 % by volume of ethanol.
2. Maximum boiling azeotrope.
The solutions showing negative deviation from Raoult’ s law. For instance, solution of nitric acid and water has the approximate arrangement, 68 % nitric corrosive and 32 % water by mass, with a breaking point of 393.5 K.
Properties of solution affected by vapour pressure
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Vapour pressure of solution decreases on addition of a non-volatile solute to a volatile solvent.
Properties of solutions affected by the decrease of vapour pressure includes-
1. Relative lowering of vapour pressure of the solvent 2. Depression of freezing point of the solvent 3. Elevation of boiling point of the solvent and 4. Osmotic pressure of the solution.
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These properties of solution depend on the number of solute particles present in the solution regardless of their nature relative to the total number of particles present in the solution. These