Page 25 - Ranger PT3 2022 science

Science PT3 Chapter 5 Water and Solution
Solubility
1. Solubility of a substance is the maximum quantity of solute that can dissolve in
100 ml of solvent at a given temperature.
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2. The solubility depends on how fast the solute dissolves in a solvent at a given quantity.
3. The following experiment aims to study the factors that affect the solubility of
a solute.
(A) Temperature of the solvent
The higher the temperature of the solvent, the higher the solubility.

Thermometer
Glass rod

Fine salt 100 ml of
distilled water
Bunsen burner
100 ml of
Fine salt distilled water
J K
(a) Salt dissolves faster in water with high temperature than in water at
room temperature.
(b) A solvent with a high temperature increases the movements of the
solvent’s particles. As a result, the solvent’s particles collide against
the salt particles more frequently.
(B) Rate of stirring
The higher the stirring rate, the higher the solubility.
Stirred Stirred
Form 2
fast slowly

100 ml water +
Form 2
5 g of fine salt
Beaker L Beaker M
(a) Salt dissolves faster when stirred fast.
(b) The solute’s particles move faster when stirred faster, thus causing
the solute’s particles to collide against each other more often.
(C) Size of the solute
The smaller the size of the solute, the higher the solubility.

100 ml
5 g of of water 5 g of coarse
fine salt
Beaker N Beaker O salt
(a) Fine salt dissolves faster compared to coarse salt.
(b) The smaller size of a solute has a larger total surface area to collide
with the solvent’s particles.

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