CAPF AC : 2023 

Pure, demineralized water, free from all soluble minerals salts is obtained by which of the following method?

a) passing water through micro-filtration membrane

b) Calgon’s method

c) passing water through a cation exchange and an anion exchange resin bed

d) by boiling

Answer: C

Explanation:

Demineralized Water also known as Deionized Water, Water that has had its mineral ions removed.

Mineral ions such as cations of sodium, calcium, iron, copper, etc and anions such as chloride, sulphate, nitrate, etc are common ions present in Water.

Deionization is a physical process which uses specially-manufactured ion exchange resins which provides ion exchange site for the replacement of the mineral salts in Water with Water forming H+ and OH- ions.