Question 1

Which of the following best describes the Tyndall Effect observed in colloidal systems?

Accepted Answer

It is the scattering of light by particles in the mixture, making the path of light visible.

Question 2

A pharmaceutical scientist is preparing a colloidal solution of gelatin in water. Which classification does this colloid fall under?

Accepted Answer

Lyophilic colloid

Question 3

Which property distinguishes a true solution from a colloidal dispersion?

Accepted Answer

Particles in true solutions are invisible even under an electron microscope.

Question 4

Which of the following is a correct statement about Brownian motion in colloidal systems?

Accepted Answer

It is the random movement of colloidal particles caused by collisions with solvent molecules.

Question 5

Which of the following pharmaceutical applications relies on the formation of an emulsion?

Accepted Answer

Formulation of oil-in-water creams using an emulsifying agent

Question 6

A colloidal system consists of two phases. What are they?

Accepted Answer

Dispersed phase and dispersion medium

Question 7

Which of the following statements about lyophobic colloids is TRUE?

Accepted Answer

They require stabilizers to prevent precipitation.

Question 8

What is the critical micelle concentration (CMC) in the context of association colloids?

Accepted Answer

The concentration at which amphiphiles aggregate to form micelles.

Question 9

Which of the following is NOT a property of colloidal dispersions?

Accepted Answer

Can be filtered using standard filter paper.

Question 10

A student observes that a mixture of water and milk scatters light when a flashlight is shone through it, but a solution of salt in water does not. What phenomenon is being demonstrated?

Accepted Answer

Tyndall effect

Question 11

Which of the following best explains why lyophilic colloids are more stable than lyophobic colloids?

Accepted Answer

Lyophilic colloids have a protective layer of solvent molecules and charge, preventing aggregation.

Question 12

Which of the following is an example of an association colloid?

Accepted Answer

Soap molecules forming micelles in water

Question 13

Which equation best represents the structure of a simple soap molecule used as a detergent?

Accepted Answer

$ \mathrm{C_{17}H_{35}COO^- Na^+} $

Question 14

Which of the following statements about colloidal stability is correct?

Accepted Answer

Stable colloids have particles that remain dispersed in the medium at all times.

Question 15

A pharmaceutical gel is prepared using gelatin. What type of colloid is this?

Accepted Answer

Lyophilic gel

Question 16

Which of the following is a correct description of an aerosol colloid?

Accepted Answer

Liquid droplets dispersed in a gas

Question 17

Which process is used to separate colloidal particles from the dispersion medium?

Accepted Answer

Ultracentrifugation

Question 18

Which of the following is a key difference between lyophilic and lyophobic colloids?

Accepted Answer

Lyophilic colloids have higher viscosity than the dispersion medium.

Question 19

Which of the following best describes the role of an emulsifying agent in pharmaceutical emulsions?

Accepted Answer

It prevents the dispersed droplets from coalescing by forming a protective layer.

Colloids: Properties, Classification, and Pharmaceutical Applications

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