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dissolves completely, but if we add sand in water, it will not dissolve and will settle at the
bottom when left undisturbed for some time. Thus, we note that some substances are
soluble (dissolve completely) and some are insoluble (that do not dissolve).
Soluble substances are those substances that dissolve completely in water or any other
solvent to form a solution. Sugar, salt, coff ee, turmeric powder and soap are some solid
substances that are soluble in water.
mix
salt sugar soap powder solutes dissolve
completely in water
Soluble solutes
Milk and alcohol are liquids that dissolve in water, and when
two liquids dissolve completely, they are called miscible liquids. Did You Know!
Lemonade is a
For example, milk and water are miscible liquids.
solution of water,
Some gases like oxygen, carbon dioxide and chlorine dissolve lemon juice and
in water. Carbonated drinks are the best examples which show sugar.
the solubility of gases in water.
Insoluble substances are those substances that do not dissolve in water or any other
solvent. Sand, stone, fl our, wax and chalk powder are some substances that do not
dissolve in water.
mix
sand stone chalk powder solutes do not dissolve in water,
and settle at the bottom
Insoluble solutes
Some liquids do not dissolve completely when mixed together. Such liquids are called
immiscible liquids. When immiscible liquids are mixed, the lighter liquid fl oats on the
heavier liquid. For example, if we mix oil with water, we can see a distinct layer of oil
fl oating on the surface of water, as it is lighter than water.
Some gases like hydrogen, nitrogen and helium are insoluble in water.
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