Question

Which of the following does not form an acidic salt?
(A) Phosphoric acid
(B) Carbonic acid
(C) Hydrochloric acid
(D) Sulphuric acid

Answer 1

Hint :Salts can be classified as acidic or basic depending upon the relative strengths of the acids and bases being used in the neutralization reaction to form that particular salt. Only strong acids are capable of forming an acidic salt.

Complete Step By Step Answer:
Acidic or basic substances are characterized by their pH values in aqueous solution. A pH value below seven makes the substance acidic and a pH value above seven makes the substance basic in nature. A pH value of exact seven suggests that the substance is neutral like water.
Salt formation is a consequence of reaction between an acid and a base which contribute an anion and a cation respectively. Hydrolysis of salts gives back the parents acids and bases which helps in determining the nature of the salts.
Strong acids participating in the neutralization reaction are capable of giving acidic salts provided that the counter base being used is not an equally strong base. Weak acids do not give acidic salts.
The given acid can be classified as strong or weak acids.
Phosphoric acid: weak acid
Carbonic acid: weak acid
Hydrochloric acid: strong acid
Sulphuric acid: strong acid.
Hence, Phosphoric and Carbonic acid do not form acidic salts as they are weakly acidic in nature.

Note :
A comparison of the acidic strengths of salts being formed from different acids can be made keeping in mind that the counter remains the same for all the acids. If different acids react with different bases then the acidic or basic nature of salts cannot be compared by comparing the acids alone.