Page 84 - ICSE Chemistry 6

Observa on: You will observe that the sugar se les down at the bo om of beaker A while it dissolves in
water in beaker B.
Conclusion: This shows that on s rring the solu on, solubility of the solute increases.

Activity 4.8

Aim: To observe the eff ect of size of solute par cles on the forma on of a solu on

Materials required: 2 beakers, some water, a lump of common salt, some free-fl owing common salt, a
spoon
Procedure
• Take two beakers and label them as A and B.
• Pour equal amount of water in each beaker.
• Now put a lump of common salt in beaker A and a teaspoon of free-fl owing common salt in
beaker B. You can also use sugar cubes and powdered sugar.
• Now s r both the solu ons one by one and no ce the me taken by each of the solutes to dissolve.

Observa on: You will observe that the salt in beaker A takes a longer me to dissolve as compared to the
salt in beaker B.
Conclusion: This proves that smaller the par cle size of solute, faster the solu on will be formed.

Activity 4.9

Aim: To observe the eff ect of increase in temperature on the forma on of a solu on

Materials required: Beaker, sugar, spoon, burner
Procedure
• Take beaker B from the previous ac vity.
• Now add some sugar to it and s r the solu on.
• Con nue adding the sugar ll no more of it can be dissolved in the solu on.
• Now heat this beaker.
• Again add a teaspoon of sugar to it.
Observa on: You will observe that more sugar can be dissolved in the beaker on hea ng the solu on.

Conclusion: This shows that the solubility of a solute increases on increasing the temperature.

Saturated and Unsaturated Solutions

In Ac vity 4.9, we have observed that if we con nue adding
sugar to the solu on, a stage is soon reached when no more of Thirst for Knowledge
it can be added. However, if we increase the temperature of the
The point at which the solu on
solu on, more solute can be added to it. Thus, on the basis of the
cannot further dissolve a solute is
ability of solu ons to dissolve more solute we can divide them known as satura on point.
into three types—saturated solu on, unsaturated solu on and
supersaturated solu on.

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