© examsnet.com
Question : 6
Total: 26
What is meant by positive deviations from Raoult's law? Give an example. What is the sign of ∆ mix H
OR
Define azeotropes. What type of azeotrope is formed by positive deviation from Raoult's law? Give an example.
OR
Define azeotropes. What type of azeotrope is formed by positive deviation from Raoult's law? Give an example.
Solution:
When vapour pressure of solution is higher than that predicted by Raoult's law the intermolecular attractive forces between the solute-solvent (AB) molecules are weaker than those between the solute-solute and solvent-solvent molecules (A-A or B-B molecules).
Eg. ethanol-acetone / ethanol-cyclohexane /CS 2 − ∆ mix H
OR
(a) Azeotropes are binary mixtures having the same composition in the liquid and vapour phase and boil at a constant temperature.
(b) Minimum boiling azeotrope
eg-ethanol + water or any other example
Eg. ethanol-acetone / ethanol-cyclohexane /
OR
(a) Azeotropes are binary mixtures having the same composition in the liquid and vapour phase and boil at a constant temperature.
(b) Minimum boiling azeotrope
eg-ethanol + water or any other example
© examsnet.com
Go to Question: