Colloidal Dispersion Quiz

What is the meaning of Colloid in Greek?

Answer explanation

The term 'Colloid' comes from the Greek word 'kolla', meaning 'glue'. It refers to a substance that has properties between those of a solution and a suspension, resembling a sticky or glue-like consistency.

What is a colloidal dispersion or dispersed system?

Answer explanation

A colloidal dispersion, or dispersed system, is a mixture where fine particles are evenly distributed within a continuous medium, such as liquid or gas, without settling out. Examples include milk and fog.

What are some examples of colloidal dispersions?

• Emulsions

• Gels

• Foams

• Sols

Answer explanation

Colloidal dispersions include emulsions (liquid-liquid), gels (solid-liquid), foams (gas-liquid), and sols (solid-liquid). All these examples illustrate the mixture of different phases, making them colloidal in nature.

What shapes can colloidal particles assume?

• Spheres and globules

• Short rods and prolate ellipsoids

• Oblate ellipsoids and flakes

• Long rods and threads

• Loosely coiled threads, branched threads

Answer explanation

Colloidal particles can take various shapes, including spheres, short rods, prolate ellipsoids, oblate ellipsoids, flakes, long rods, threads, and loosely coiled or branched threads, making all provided options correct.

How does the shape of colloidal particles affect the flow, sedimentation, and osmotic pressure?

Answer explanation

The shape of colloidal particles influences their flow and sedimentation rates; elongated particles may align and flow more easily, while spherical particles settle faster. Additionally, shape affects osmotic pressure by altering particle interactions.

How does the shape of the dispersed phase influence the viscosity of the dispersion?

Answer explanation

The shape of the dispersed phase affects how particles interact and move within the dispersion. Irregular shapes can increase resistance to flow, leading to higher viscosity, while spherical shapes typically result in lower viscosity.