The complete lecture — solutions come alive in the live panel as you read. Scroll down; the animation keeps pace, and you can mix a solution yourself.
1 — Solutions
- Solution — a homogeneous mixture; solute (smaller amount) + solvent (larger). "Like dissolves like".
2 — Concentration units
MolarityM = moles of solute / volume (dm³)
Drag the sliders in the live panel to dissolve NaCl and read off the molarity.
3 — Solubility & saturation
- Saturated — holds the maximum solute; excess stays undissolved.
4 — Effect of temperature & pressure
Henry's lawgas solubility ∝ partial pressure
5 — Colligative properties
- Lowering of vapour pressure · boiling-point elevation · freezing-point depression · osmotic pressure.
6 — Vapour pressure, boiling & freezing
RaoultΔTb = Kb·m (up) · ΔTf = Kf·m (down)
7 — Osmosis & osmotic pressure
van 't Hoffπ = C R T
8 — Colloids
| Mixture | Particle |
|---|
| solution | < 1 nm |
| colloid | 1–1000 nm |
| suspension | > 1000 nm |
9 — Types of colloids
| Type | Example |
|---|
| sol | paint |
| emulsion | milk |
| foam | cream |
| aerosol | fog |
10 — Properties of colloids
- Tyndall effect — colloid particles scatter light. Also: Brownian motion, coagulation, dialysis.
11 — Worked numericals
molarity
4 g NaOH in 500 cm³: moles=0.1, M = 0.1/0.5 = 0.2 M
dilution
2 M HCl → 100 cm³ of 0.5 M: V₁ = (0.5×100)/2 = 25 cm³
12 — Exam recap
- Solute/solvent; concentration units.
- Solubility & saturation; Henry's law.
- The four colligative properties.
- Boiling/freezing changes; osmotic pressure.
- Colloids vs solutions/suspensions; types.
- Tyndall effect, Brownian motion, dialysis.