Question

Using which of the following permanent hardness of water is reduced? *



Washing soda

Baking soda

Gypsum

Sodium hydroxide

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Answer 1

Answer:

Washing soda

Explanation:

Hard water can be softened by adding washing soda (sodium carbonate) which removes the calcium ions in a precipitation reaction. Alternatively, the hard water can be passed through an ion-exchange resin in a column. Sodium ions replace the calcium ions in the water as it passes through the column.