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Question
Which of the following compounds is used for water softening?
Options
\[\ce{Ca3(PO4)2}\]
\[\ce{Na3PO4}\]
\[\ce{Na6P6O18}\]
\[\ce{Na2HPO4}\]
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Solution
\[\ce{Na6P6O18}\]
Explanation:
Sodium hexametaphosphate \[\ce{(Na6P6O18)}\], commercially called ‘calgon’, is used to remove hardness from water.
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