Question

Calgon removes hardness by forming complex compounds with the ${\text{C}}{{\text{a}}^{2 + }}$ and ${\text{M}}{{\text{g}}^{2 + }}$ ions of hard water or by adsorption.
(A) True
(B) False

Answer 1

Calgon is an American brand of bath and beauty products and water softeners. The original product consisted of sodium hexametaphosphate powder (amorphous sodium polyphosphate). Calgon is a detergent powder which is sold worldwide originating from the United States.

Complete Step-by-Step solution
The chemical formula of Calgon is ${\text{N}}{{\text{a}}_6}{{\text{P}}_6}{{\text{O}}_{18}}$ . The name of the chemical compound is sodium hexametaphosphate.
Calgon is manufactured as a powder and it is made into use by mixing it with the water and it forms a soluble substance.
The reaction of Calgon with water is given below as:
${\text{N}}{{\text{a}}_2}\left[ {{\text{N}}{{\text{a}}_4}{{\left( {{\text{P}}{{\text{O}}_3}} \right)}_6}} \right] + 2{\text{CaS}}{{\text{O}}_4} \to 2{\text{N}}{{\text{a}}_2}{\text{S}}{{\text{O}}_4} + {\text{N}}{{\text{a}}_2}\left[ {{\text{C}}{{\text{a}}_2}{{\left( {{\text{P}}{{\text{O}}_3}} \right)}_6}} \right]$
The compound at the end ${\text{N}}{{\text{a}}_2}\left[ {{\text{C}}{{\text{a}}_2}{{\left( {{\text{P}}{{\text{O}}_3}} \right)}_6}} \right]$ is soluble in water.
Just as the same way as the reaction above, ${\text{M}}{{\text{g}}^{2 + }}$ in the hard water can also react and form precipitate as ${\text{N}}{{\text{a}}_2}\left[ {{\text{M}}{{\text{g}}_2}{{\left( {{\text{P}}{{\text{O}}_3}} \right)}_6}} \right]$
Similarly, ${\text{C}}{{\text{a}}^{2 + }}$ in the hard water will also make its precipitate when Calgon will be mixed in water
And the water will become free from ${\text{C}}{{\text{a}}^{2 + }}$ and ${\text{M}}{{\text{g}}^{2 + }}$ ions
So, it is true that Calgon removes hardness by forming complex compounds with the ${\text{C}}{{\text{a}}^{2 + }}$ and ${\text{M}}{{\text{g}}^{2 + }}$ ions of hard water or by adsorption.
Hence, the correct option is (A).

Additional Information
Its name was a portmanteau derived from the phrase "calcium gone". Originally promoted in bathing and cleaning for general use, it gave rise to derivative products that differed from the original composition. The molecular weight of Calgon (sodium hexametaphosphate) is $611.77\;{\text{g}}/{\text{mol}}$ .

Note
The original product was powdered sodium hexametaphosphate (amorphous sodium polyphosphate) compounded in water by ambient calcium ions and certain other cations, preventing the formation of unwanted salts and interfering with the action of soap or other detergents by those cations.