Hard and Soft Water

 

Depending on the action of soap on water, natural water is divided into hard and soft water.

HARD WATER

It does not lather readily with ordinary soap, hence wastes soap.

Hard water contains dissolved calcium and magnesium salts, bicarbonates, sulphates and chlorides.

Sources of hard water include natural water, like water from springs and rivers.

SOFT WATER

It lathers readily with ordinary soap hence does not waste soap.

Soft water does not contain dissolved salts of calcium and magnesium salts.

Sources of soft water include rainwater and distilled water.

TYPES OF HARDNESS IN WATER

1. Temporary Hardness

Temporary hardness can be removed by boiling.

This type of hardness occurs in water due to the presence of calcium and magnesium bicarbonates. [Ca(HCO₃)₂ and Mg(HCO₃)₂].

2. Permanent Hardness

Permanent hardness cannot be removed by boiling.

This type of hardness is due to the presence of calcium and magnesium, chlorides and sulphates. [CaCl₂, MgCl₂, CaSO₄, MgSO₄]