Match List I with List II:
List-I (Example of colloids)          List-II (Classification)
(a) Cheese                                 (i) dispersion of liquid in liquid
(b) Pumice stone                      (ii) dispersion of liquid in gas
(c) Hair cream                           (iii) dispersion of gas in solid
(d) Cloud                                    (iv) dispersion of liquid in solid
Choose the most appropriate answer from the options given below:

Classification of Colloids:

| Dispersed Phase | Dispersion Medium | Type of Colloid | Examples |

|---|---|---|---|

| Solid | Solid | Solid Sol | Coloured glasses, gem stones |

| Solid | Liquid | Sol | Paints, cell fluids |

| Solid | Gas | Aerosol | Smoke, dust |

| Liquid | Solid | Gel | Cheese, butter, jellies |

| Liquid | Liquid | Emulsion | Milk, hair cream |

| Liquid | Gas | Aerosol | Fog, mist, cloud |

| Gas | Solid | Solid Sol | Pumice stone, foam rubber |

| Gas | Liquid | Foam | Froth, whipped cream, soap lather |

Match List-I with List-II:

(a) Cheese

Cheese is a gel, which is dispersion of liquid in solid.

$$\mathrm{(a)\rightarrow(iv)}$$

(b) Pumice stone

Pumice stone is a solid sol, which is dispersion of gas in solid.

$$\mathrm{(b)\rightarrow(iii)}$$

(c) Hair cream

Hair cream is an emulsion, which is dispersion of liquid in liquid.

$$\mathrm{(c)\rightarrow(i)}$$

(d) Cloud

Cloud is an aerosol, which is dispersion of liquid in gas.

$$\mathrm{(d)\rightarrow(ii)}$$

Therefore,

$$\boxed{(a)-(iv),\ (b)-(iii),\ (c)-(i),\ (d)-(ii)}$$