Advertisements
Advertisements
Question
You are asked to prepare hard water in your laboratory. Select a group from the following groups of salts, any salt of which you may dissolve in distilled water to obtain hard water.
(A) NaCl; Na2SO4; KCl
(B) NaCl; CaCl2; KCl
(C) CaCl2; CaSO4; MgSO4
(D) Na2SO4; CaSO4; MgSO4
Advertisements
Solution
Hardness of water is due to the presence of calcium and magnesium ions.
Presence of calcium and magnesium salts in the form of hydrogencarbonate, chloride and sulphate in water makes water ‘hard’. Hard water does not give lather with soap. Water free from soluble salts of calcium and magnesium is called soft water. It gives lather with soap easily.
So, student need to dissolve calcium chloride, calcium sulphate and magnesium sulphate in distilled water to convert it into hard water.
Hence, the correct answer is option (C).
APPEARS IN
RELATED QUESTIONS
Give any two uses of common salt (sodium chloride).
Complete and balance the following chemical equation:
\[\ce{NaCl + NH3 + H2O + CO2 ->}\]
Name three products of the chlor-alkali process. State two uses of each of these products.
Give the names and formulae of any two salts. Also name the acids and bases from which these salts may be obtained.
The salt whose aqueous solution will have no effect on either red litmus or blue litmus is ______.
When the concentrated aqueous solution of substance X is electrolysed, then NaOH, Cl2 and H2 are produced. Name the substance X. What is the special name of this process?
Taking sodium carbonate as an example, give the meaning of the following terms:
Anhydrous
Sodium carbonate is a basic salt because it is a salt of a ____________.
The acid reacts with a base to form a neutral product called ______.
An aqueous solution of a salt turns blue litmus to red. The salt could be the one obtained by the reaction of ______.
