solution_part3.ppt CHEMISTRY CLASS 12

SOLUTION

1. SOLUTIONS
CONCEPT MAP
•Method of expressing the concentration of the
solution: molarity , molality , mole fraction , parts per
million.
•Solubility of solid in liquid , solubility of gas in liquid.
•Raoult’s law , ideal and non-ideal solution
•Colligative properties: Relative lowering of vapour
pressure , elevation in boiling point , depression in
freezing point , osmotic pressure
•Abnormal molecular mass , Van’t hoff factor

2. Vapour pressure
The pressure excerted by the
vapours above the liquid surface
in equillibrium with the liquid at
the given temperature is called
vapour pressure .

3. Raoult’s law states that at a given temperature , for a solution of
volatile liquid , the partial vapour pressure of each component of
the solution is directly proportional to its mole fraction present in
solution
Raoult’s Law

4. Solution containing non volatile solute

5. Raoult’s Law for solution containing
non-volatile solute

7. Ideal and Non-Ideal solution

8. IDEAL AND NON-IDEAL SOLUTION

9. Azotropes are binary mixture having same
composition in liquid and vapour phase and boil at
constant temperature.
There are two types of azotropes:
Minimuim boiling azotropes: These solutions show
positive deviation from Raoult’s lawe.g Ethanol
and water
Maxmium boiling azotropes: These solutions show
negative deviation from Raoult’s lawe.g nitric acid
and water
AZOTROPES

10. Questions:
1. Define Roault’s law .
2. State Raoult;s law for solution containing volatile components.
3. What is the similarites between Raoult’s law and Henry’s law?
4. Name the solution which follow Raoult’s law at all concentrations and temperature.
5. How Raoult’s law is formulated for solutions of non volatile solutes?
6. What type of deviation shows the formation of maximium boiling azotropes?
7. What are azotropes?
8. What is meant by positive deviation from Raoult’s law?
9. What type of azotropes formed by negative deviation from Raoult’s law?
10. Explain Why a solution of chloroform and acetone shows negative deviation from
Raoult’s law?
11. Taking suitable example explain the meaning of positive and negative deviation
from Raoult’s law.
12. Draw a diagram to illustrate the relationship between vapour pressure and mole
fraction of components in a solution to represent negative deviations.
13. What is the effect of adding non-volatile solute on vapour pressure of the solution.