Solutions – Class 12 Chemistry Notes | CBSE NCERT Based
📚 Chapter: Solutions – Class 12 Chemistry Notes
---
🔸 Introduction:
A solution is a homogeneous mixture of two or more substances. This chapter discusses different types of solutions, concentration terms, Raoult's law, and colligative properties.
---
🔹 1. Types of Solutions
Solute Solvent Example
Solid Liquid Sugar in water
Liquid Liquid Alcohol in water
Gas Liquid Oxygen in water
Binary solution: Two components (solute + solvent)
---
🔹 2. Concentration Terms
Mass % = (Mass of solute / Mass of solution) × 100
Mole Fraction (χ) = moles of one component / total moles
Molarity (M) = moles of solute / volume of solution in L
Molality (m) = moles of solute / mass of solvent in kg
---
🔹 3. Solubility
Solubility of solid in liquid increases with temperature
Solubility of gas in liquid decreases with temperature but increases with pressure
Henry’s Law:
p = KH × x
(p = partial pressure, x = mole fraction of gas)
---
🔹 4. Raoult’s Law
For liquid-liquid solutions:
Partial vapour pressure ∝ mole fraction
→ pA = pA⁰ × xA
→ Total pressure = pA + pB
Ideal solution: Obeys Raoult’s law
Non-ideal solution: Shows deviation (positive or negative)
---
🔹 5. Colligative Properties
Depend on number of solute particles:
1. Relative Lowering of Vapour Pressure
Δp / p⁰ = χB
2. Elevation of Boiling Point
ΔTb = Kb × m
3. Depression of Freezing Point
ΔTf = Kf × m
4. Osmotic Pressure (Ï€)
Ï€ = CRT
(C = concentration, R = gas constant, T = temp)
---
🔹 6. Abnormal Molar Mass & van’t Hoff Factor
Observed molar mass ≠ actual due to association/dissociation
van’t Hoff factor (i) = observed colligative property / calculated property
---
📌 Conclusion:
Solutions chapter helps in understanding concentration, solubility, vapor pressure, and effects of solutes. These concepts have practical applications in chemistry, biology,
and medicine.
---
✍️ Written by: Shahid – Study with Shahid
🔗 Visit: https://shahidnotes12.blogspot.com
Comments
Post a Comment