Surface Chemistry

Step-by-Step Solution

Step 1: What Is a Multimolecular Colloid?

First, let’s understand what a colloid is. A colloid is a mixture where tiny particles are spread out in a medium but don’t settle down—like milk or fog. There are different types of colloids, and one type is called a multimolecular colloid. This happens when many small molecules come together to form particles that are big enough to be colloidal (usually between 1 nm and 1000 nm in size). These particles are made up of aggregates of molecules. Cool, right? Now, let’s see which option fits this!

Step 2: Check Each Option

Let’s look at each substance and decide if it can form a multimolecular colloid:

• Option 1: Cellulose

  Cellulose is a complex carbohydrate found in plant cell walls, made up of long chains of glucose molecules. While it’s a big molecule, it doesn’t typically form colloidal particles by aggregating small molecules in the way multimolecular colloids do. It’s more of a macromolecule on its own.

• Option 2: Plastic

  Plastics are synthetic polymers, like polyethylene, made of long chains of repeating units. They are usually solid materials and don’t form colloidal dispersions by aggregating small molecules into colloidal-sized particles. So, plastic isn’t a multimolecular colloid.

• Option 3: S8 molecule

  S8 refers to a molecule of sulfur, where eight sulfur atoms form a ring. This is a single molecule, not an aggregate of many small molecules forming a larger colloidal particle. Multimolecular colloids need many molecules to come together, so S8 doesn’t fit.

• Option 4: Starch

  Starch is a carbohydrate stored in plants, made of many glucose molecules. In water, starch can break down into smaller units and form colloidal particles when these units aggregate into clusters that are the right size (1 nm to 1000 nm). This makes starch a classic example of a multimolecular colloid, especially in things like starch suspensions!

Step 3: Pick the Right One

From our list, Cellulose and Plastic are large molecules but don’t form colloids through aggregation of small molecules. The S8 molecule is a single entity, not a colloid. Starch, however, fits perfectly because its glucose units can aggregate into colloidal-sized particles in a suitable medium like water. So, Starch is our winner!

Step 4: Match with Options

The options provided are:

• Option 1: Cellulose
• Option 2: Plastic
• Option 3: S8 molecule
• Option 4: Starch ✔ Correct

Since Starch is the substance that forms a multimolecular colloid, the correct answer is Option 4.

Final Answer: Option 4 (Starch) is correct.

Froth is not a solution but rather a colloid. A colloid is a mixture in which small particles are dispersed throughout a medium. In the case of froth, it is typically a colloid consisting of gas bubbles dispersed in a liquid or solid medium.
For example, froth can be formed by whipping or agitating a liquid such as milk, resulting in the incorporation of air bubbles into the liquid. Similarly, froth can be produced in certain industrial processes or natural phenomena.
Therefore, froth is not specifically a solution of any particular substance, but rather a colloidal dispersion of gas bubbles in a liquid or solid medium.