Question

Which of the following salts are more soluble in acidic solution than in pure water?

(A) Al(OH)3,
(B) BaF2,
(C) PbCl2,
(D) Hg2Br2,
(E) NiS,
(F) AgI

Answer 1

The solubility of salts with anions from weak bases increases in acidic solutions. Al(OH)3 is an example of such a salt, as it becomes more soluble when acid protonates the hydroxide ions, leading to increased solubility. So the correct option is A.

Step-by-step explanation:

The solubility of salts in acidic solutions compared to pure water can be understood in the context of the common ion effect and Le Chatelier's principle. Salts composed of a weak base and a strong acid will be more soluble in an acidic solution due to the protonation of the anion, which reduces the common ion effect and drives the dissolution reaction forward.

Al(OH)3 is a salt of a weak base (Al(OH)₂⁺) and a strong base (OH⁻). The presence of an acid such as HCl will protonate the OH⁻, forming water and thus removing the common ion effect on the solubility equilibrium. As a result, the solubility of Al(OH)3 increases in an acidic solution compared to pure water.

Other compounds such as BaF2, PbCl2, Hg2Br2, NiS, and AgI are also likely to have increased solubility in acidic solutions if they contain anions that can react with the added H⁺ ions. For example, NiS, containing the weak base anion S²⁻, will react with H⁺ to form H₂S, enhancing its solubility in acidic solutions.

Answer 2

one way to look at it is to determine whether the compound is acidic or basic. basic compounds will dissolve more easily in acid

A) Al(OH)3 is the hydroxide of a metal and this is basic. hence this will dissolve better in acid than pure water ( in fact Al(OH)3 is amphoteric meaning it can dissolve in both acid and base)

B) BaF2 is the salt of a strong base Ba(OH)2 and weak acid HF, hence the nature of BaF2 is slightly basic, this will dissolve better in acidic solution

C) PbCl2 is the salt of weak base Pb(OH)2 and strong acid HCl, hence the nature of PbCl2 is slightly acidic, it won’t be more soluble in acidic solution

D) Hg2Br2 is the salt of weak base Hg2(OH)2 and strong acid HBr. the nature of Hg2Br2 is acidic hence, it wont dissolve better in acidic solution

E) NiS is the salt of a very weak base Ni(OH)2 hence this NiS will be acidic in nature nd wont dissolve in acidic solution

F) AgI is the salt of a very strong acid HI and weak base AgOH. nature will be acidic and wont dissolve in acidic solution



in conclusion only Al(OH)3 and BaF2 are more soluble in acidic solution than in pure water as both are slightly basic