how Na2CO3 remove the hardness of water
Answers
Explanation:
Sodium carbonate, Na2CO3, is also known as washing soda. It can remove temporary and permanent hardness from water. Sodium carbonate is soluble but calcium carbonate and magnesium carbonate are insoluble.
The carbonate ions from sodium carbonate react with the calcium and magnesium ions in the water to produce insoluble precipitates. For example:
calcium ions + sodium carbonate → calcium carbonate + sodium ions
Ca2+(aq) + Na2CO3(aq) → CaCO3(s) + 2Na+(aq)
The water is softened because it no longer contains dissolved calcium ions and magnesium ions. It will form lather more easily with soap.
However, the calcium carbonate and magnesium carbonate precipitates to form limescale. As well as being unsightly on your taps, it can also clog up pipes in heating systems (causing them to break down). This makes treatment with sodium carbonate suitable for softening water only in certain circumstances - such as softening water for hand washing clothes.”