More Separation Techniques 🧪

5. Chromatography

Used for: Separating solutes dissolved in the same solvent

Kroma (Greek) = Colour

Chromatography Diagram:

    Before          After Water Rises
    ┌────┐          ┌────┐
    │    │          │ 🔵 │ ← Blue dye (more soluble)
    │    │          │    │   
    │    │    →→    │ 🟢 │ ← Green dye
    │    │          │    │
    │ ●  │ Ink      │ 🟡 │ ← Yellow dye (less soluble)
    │────│          │────│ ← Original ink spot
    │~~~~│ Water    │~~~~│
    └────┘          └────┘

📝 Exam tip: More soluble = rises higher

Applications:

• 🎨 Separating colours in dye
• 💊 Separating drugs from blood

---

6. Simple Distillation

Used for: Miscible liquids with difference in BP > 25°C

Distillation Apparatus Diagram:

                    Thermometer
                        │
        ┌───────────────┼───────────────┐
        │           ┌───┴───┐           │
        │           │ bulb  │           │
        │           └───────┘           │
        │  Round          Side arm      │
        │  bottom ────────────────→→    │
        │  flask              ↓         │
        │     ↑           Condenser     │
        │ Mixture         ┌─────────┐   │
        │   ~~~          ↓│ ▓▓▓▓▓▓▓ │↓  │  (Cold water
        │    ↑           ↓│ ▓▓▓▓▓▓▓ │↓  │   flows around)
        │  🔥 Heat       ↓│ ▓▓▓▓▓▓▓ │↓  │
        └────────────────↓└────┬────┘↓──┘
                              ↓
                         Collecting flask
                         (Distillate)

---

7. Fractional Distillation

Used when: Boiling point difference is less than 25°C

Fractional Distillation Column:

                    Thermometer
                        │
                    ┌───┴───┐
                    │       │
                ┌───┴───────┴───┐
                │ ○ ○ ○ ○ ○ ○ ○ │ ← Glass beads
                │ ○ ○ ○ ○ ○ ○ ○ │   (fractionating
                │ ○ ○ ○ ○ ○ ○ ○ │    column)
                │ ○ ○ ○ ○ ○ ○ ○ │
                └───────┬───────┘
        ┌───────────────┴───────────────┐
        │          Mixture              │
        │            ~~~~               │
        └───────────────────────────────┘
                      🔥

📝 Glass beads provide surface for repeated condensation

Applications:

• 🛢️ Petroleum refining
• 🌬️ Separation of gases from air

---

Separation of Gases from Air

Flow Diagram:

    AIR → Compress → Cool → LIQUID AIR → Fractional → GASES
           (high P)   (low T)           Distillation   SEPARATE

    ┌──────────────────────────────────────┐
    │        FRACTIONAL DISTILLATION       │
    │               COLUMN                 │
    ├──────────────────────────────────────┤
    │   Nitrogen (-196°C) ← Top (lowest BP)│
    │   Argon (-186°C)    ← Middle         │
    │   Oxygen (-183°C)   ← Bottom (highest BP)
    └──────────────────────────────────────┘