Discussion Forum

Reaction of Calgon with hard water  containing  $Ca^{2+}$ ion produce

Answer:

Explanation:

Calgon is a trading name of a complex salt, sodium hexametaphosphate $(NaPO_{3})_{6}$ . Calgon ionises to give a complex anion. The addition of Calgon to hard water to causes the calcium ions of hard water to displace sodium ions from the anion of Calgon and form a complex with Calgon.

$(NaPO_{3})_{6}$  or

  $Na_{2}(Na_{4}P_{6}O_{18})\rightarrow 2Na^{+}+Na_{4}P_{6}O_{18}^{2-}$(complex anion)

 $Ca^{2+}$(from hard water)+ $Na_{4}P_{6} O_{18}^{2-}$( Anion of calgon)  $\rightarrow$ $2 Na^{+}+ CaNa_{2}P_{6}O_{18}^{2-}$   (  Goes into solution)