Question

Which of the following compounds is used for water softening?

• A. $Ca_{3}(PO_{4})_{2}$
• B. $Na_{3}PO_{4}$
• C. $Na_{6}P_{6}O_{18}$
• D. $Na_{2}HPO_{4}$

Answer 1

Answer: (C)

$Na_{6}P_{6}O_{18}$

Answer 2

: Sodium hexametaphosphate $(Na_{6}P_{6}O_{18})$ commercially called calgon’ is used for water softening.