Which of the following statement is wrong regarding permanent hardness?
(a) It is also called carbonate hardness
(b) It is due to the presence of sulfates, chlorides and nitrates of calcium and magnesium
(c) It cannot be removed by boiling
(d) It requires special methods of water softening to get removed
The question was posed to me in an internship interview.
My doubt is from Chemical Characteristic of Water in portion Quality of Water of Environmental Engineering