Class 12 Chemistry - Solutions Chapter Notes
1. Definition of Solution:
A solution is a homogeneous mixture of two or more substances.
2. Types of Solutions:
Based on physical state:
- Solid in Liquid (e.g., salt in water)
- Liquid in Liquid (e.g., alcohol in water)
- Gas in Liquid (e.g., CO2 in water)
3. Concentration Terms:
- Molarity (M) = moles of solute / volume of solution (L)
- Molality (m) = moles of solute / mass of solvent (kg)
- Mole Fraction (X) = moles of component / total moles
4. Henry's Law:
The solubility of gas in liquid is proportional to pressure.
p = KH × x
5. Raoult’s Law:
Partial pressure of component = mole fraction × vapour pressure
6. Ideal vs Non-Ideal Solutions:
- Ideal: obey Raoult’s law
- Non-ideal: show deviation (positive/negative)
7. Colligative Properties:
Depend on number of particles:
- Relative lowering of vapour pressure
- Elevation in boiling point
- Depression in freezing point
- Osmotic pressure
8. Osmosis:
Flow of solvent from low concentration to high concentration through semipermeable membrane.
9. van’t Hoff Factor (i):
i = observed colligative property / calculated value
10. Abnormal Molar Mass:
Due to association or dissociation of solute particles.
