Consider the following pairs of Colloids and their Dispersing Medium: 1. Smoke : Gas 2. Shaving cream : Liquid 3. Jelly : Solid How many of the above pairs are correctly matched?

The correct option is All three Explanation Colloids are heterogeneous mixtures consisting of two phases: the dispersed phase (the substance distributed) and the dispersion medium (the substance in which the phase is suspended). The classification of colloids depends on the physical state (Gas, Liquid, or Solid) of these two components. Statement-wise Analysis: - Pair 1: Correct. Smoke is a type of colloid known as a Solid Aerosol. It consists of solid particles (dispersed phase) suspended in a gas (dispersion medium). Therefore, the dispersing medium is Gas. - Pair 2: Correct. Shaving cream is a type of colloid known as a Foam. It consists of gas bubbles (dispersed phase) trapped within a liquid (dispersion medium). Therefore, the dispersing medium is Liquid. - Pair 3: Correct. Jelly is a type of colloid known as a Gel. It consists of liquid droplets (dispersed phase) trapped within a solid network (dispersion medium). Therefore, the dispersing medium is Solid. Key Takeaway: The physical state of the dispersion medium defines the continuous phase of the colloid: Gas (Aerosols), Liquid (Sols, Emulsions, Foams), or Solid (Solid Sols, Gels).

NCERT Class 9 Science — Chapter 2: Is matter around us pure?

mcqhard

Consider the following pairs of Colloids and their Dispersing Medium:

Smoke : Gas
Shaving cream : Liquid
Jelly : Solid

How many of the above pairs are correctly matched?

Official previous-year question

Verified 1 Aug 2026.

Options

ANone
BOnly two
COnly one
DAll three

Did you get this right?

Solution

The correct option is

All three

Explanation

Colloids are heterogeneous mixtures consisting of two phases: the dispersed phase (the substance distributed) and the dispersion medium (the substance in which the phase is suspended). The classification of colloids depends on the physical state (Gas, Liquid, or Solid) of these two components.

Statement-wise Analysis:

Pair 1: Correct.
Smoke is a type of colloid known as a Solid Aerosol. It consists of solid particles (dispersed phase) suspended in a gas (dispersion medium). Therefore, the dispersing medium is Gas.
Pair 2: Correct.
Shaving cream is a type of colloid known as a Foam. It consists of gas bubbles (dispersed phase) trapped within a liquid (dispersion medium). Therefore, the dispersing medium is Liquid.
Pair 3: Correct.
Jelly is a type of colloid known as a Gel. It consists of liquid droplets (dispersed phase) trapped within a solid network (dispersion medium). Therefore, the dispersing medium is Solid.

Key Takeaway:
The physical state of the dispersion medium defines the continuous phase of the colloid: Gas (Aerosols), Liquid (Sols, Emulsions, Foams), or Solid (Solid Sols, Gels).

Your note

More from Chapter 2: Is matter around us pure?

With reference to 'Alloys', consider the following statements: 1. They are considered mixtures because they show the properties of their constituents. 2. They can be separated into their components by physical methods. 3. They have a fixed composition and cannot vary. Which of the statements given above is/are correct?

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Consider the following statements regarding the properties of metals: 1. They are generally brittle and non-ductile. 2. They are generally good conductors of heat and electricity. 3. They are sonorous. Which of the statements given above is/are correct?

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Consider the following statements about elements: 1. The majority of elements are solids. 2. Only two elements are in the gaseous state at room temperature. 3. Gallium and Cesium remain solid even at temperatures well above 303 K. Which of the statements given above is/are correct?

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In the classification of colloids, 'Cheese' and 'Butter' are examples of:

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Consider the following statements regarding the burning of wood: 1. It involves the conversion of wood into new substances like ash and smoke. 2. It is a physical change. 3. It is an irreversible process. Which of the statements given above is/are correct?

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The correct option is

All three

Explanation

Statement-wise Analysis:

Pair 1: Correct.
Smoke is a type of colloid known as a Solid Aerosol. It consists of solid particles (dispersed phase) suspended in a gas (dispersion medium). Therefore, the dispersing medium is Gas.
Pair 2: Correct.
Shaving cream is a type of colloid known as a Foam. It consists of gas bubbles (dispersed phase) trapped within a liquid (dispersion medium). Therefore, the dispersing medium is Liquid.
Pair 3: Correct.
Jelly is a type of colloid known as a Gel. It consists of liquid droplets (dispersed phase) trapped within a solid network (dispersion medium). Therefore, the dispersing medium is Solid.

Key Takeaway:
The physical state of the dispersion medium defines the continuous phase of the colloid: Gas (Aerosols), Liquid (Sols, Emulsions, Foams), or Solid (Solid Sols, Gels).