Question

Which of the following is insoluble in water?
(a) H₂S (b) HgCl₂
(c) Ca (NO₃)₂ (d) CaF₂

Answer 1

(d) CaF₂

Explanation:

All ionic compounds are soluble in water to some extent, but the degree of solubility varies. While some compounds dissolve almost completely, others dissolve to such a small extent that they are simply called insoluble compounds. Such compounds include calcium sulfate, silver chloride, and lead hydroxide. CaF2 is a white insoluble solid.

Option D is the answer.