Page 95 - ICSE Science 3 : E-book

Observation:
You will observe that in the fi rst case, when the water is cold, it takes more time to
dissolve sugar completely in it. In the second case, sugar is added in the beaker with

warm water. In this, sugar gets dissolved completely in very less time. This is because
the temperature of water is increased.
Result:

When the temperature of solvent is increased by warming, a solution is formed in lesser
time.

Soluble and Insoluble Substances

When you add a substance in another substance, it will either dissolve completely

in the second substance or it will not dissolve at all. On the basis of the ability of a
substance to dissolve in water, we categorise it as soluble or insoluble.

• The substances which dissolve completely in water are called soluble substances.
A few examples of soluble substances are salt, coff ee powder and sugar.

salt coff ee powder sugar

Some examples of soluble substances

• The substances which do not dissolve in water at all are called insoluble

substances. Sand, stone, chalk powder and oil are some insoluble substances.

sand stone chalk powder oil

Some examples of insoluble substances

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