Question

Assertion :${Cu}^{+},{Ag}^{+}$ are soft acids whereas ${CN}^{-},H^{-}$ are soft bases Reason: Soft acids do not possess noble gas configuration whereas soft bases have donor atom of easily polarised nature

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Hard Acids :

(i) It includes ions of alkali metals, alkaline earth metals, lighter transition metals in higher oxidation states.

(ii) Small size, high polarising power, high electronegativity and high positive oxidation state are the characteristic features of hard acids.

(iii) Their outer electrons or orbitals are not easily distorted.

Soft Acids :

(i) It includes ions of the heavier transition metals and those in lower oxidation states.

(ii) They are large-sized and their outer electrons or orbitals are easily distorted. They have low polarising power and low electronegativity.

Soft Bases :

(i) The ligands which preferably combine with soft acids are called soft bases.

(ii) Soft bases (ligands) are large sized, more polarisable and having low electronegativity.

So, ${Cu}^{+},{Ag}^{+}$ are soft acids whereas ${CN}^{-},H^{-}$ are soft bases.