Question

Calgon used as water softener is:
A.$\text{N}{{\text{a}}_{\text{2}}}\left[ \text{N}{{\text{a}}_{\text{4}}}{{\left( \text{P}{{\text{O}}_{\text{3}}} \right)}_{\text{5}}} \right]$
B.$\text{N}{{\text{a}}_{4}}\left[ \text{N}{{\text{a}}_{2}}{{\left( \text{P}{{\text{O}}_{\text{3}}} \right)}_{6}} \right]$
C.$\text{N}{{\text{a}}_{\text{2}}}\left[ \text{N}{{\text{a}}_{\text{4}}}{{\left( \text{P}{{\text{O}}_{4}} \right)}_{\text{6}}} \right]$
D.None of these

Answer 1

Hint: There are many dissolved minerals that are found in groundwater and the amount of calcium and the magnesium present in a sample of water is together known as the hardness of water.

Complete answer:
Calgon is an American brand of water softener, bath and body works, the product consists of sodium hexametaphosphate which I water would complex with ambient calcium ions and other cations preventing formation of unwanted salts and interferences by those cations with the actions of soaps and detergents. The name derived from the phrase “calcium gone”. Originally used for general use in bathing and cleansing, it gave rise to derivative products which were diverged from the original composition.
The chemical formula of sodium hexametaphosphate is$\text{N}{{\text{a}}_{4}}\left[ \text{N}{{\text{a}}_{2}}{{\left( \text{P}{{\text{O}}_{\text{3}}} \right)}_{6}} \right]$.

Hence, option B is correct.

Note:
Water softeners are specific ion exchangers that are designed to remove calcium and magnesium ions from water which together cause the permanent hardness of water and does not allow lathering of soaps in water. The water softening ion exchangers can also remove upto 5 $\text{mg/L}$of dissolved iron also. These softeners are chemical substances as well as columns containing resins and can be automatic, semi-automatic, or even manual. The ion exchanging resins can take upto the hardness causing minerals into its conditioning tank and then flushes them away from time to time. A good water softening resin may work finely upto five years and may need some maintenance in the middle.