Page 115 - Innovator's Science-8

solute, and the substance that dissolves the solute (usually water) is called
the solvent . The solute spreads evenly throughout the solvent, forming a

mixture that looks the same everywhere. For example, when sugar
dissolves in water, the sugar is the solute, and the water is the solvent,
together making a solution where you can't see the sugar particles
separately.

Solute + Solvent Solution

When a solution is formed by mixing two liquids, it is not always clear which
substance is dissolving the other. In such cases, the substance present in
smaller amount is called the solute, while the one in larger amount is called
the solvent.

Just as water can act as a solvent in liquid solutions, gases can also form
solution— with air being a common example. Air is a gaseous solution.

Since nitrogen is present in the largest amount in the air, it is considered as
the solvent, while oxygen, argon, carbon dioxide, and other gases are
considered as solutes.

HOW MUCH SOLUTE CAN A FIXED AMOUNT OF SOLVENT DISSOLVE?

Activity-1 Aim : To observe how much solute (salt) can dissolve in a fixed amount of solvents
(water) and understand the concept of satura on.
Experiential Learning
• Take a clean glass tumbler and fill it half with water.
• Add one spoon of salt into it and s r well ll it dissolves.
• Gradually add a spoonful of salt into the glass tumbler and s r.

• Observe how many spoons of salt you can add before it stops dissolving completely.
Dissolu on of salt in water
Observa on (salt dissolves/
Amount of salt taken (teaspoon)
salt does not dissolve)
One
Two
Three
Four
. . . . .

Some Discussion Points
• How many spoons of salt were you able to dissolve before some of it remained
undissolved?
• What does this indicate about the capacity of water to dissolve salt?

When you first add salt to water, it dissolves completely and forms a clear
solution. This kind of solution is called an unsaturated solution because it

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