Statement I: The number of pairs, from the following, in which both the ions are coloured in aqueous solution is 3. [Sc³⁺, Ti³⁺], [Mn²⁺, Cr²⁺], [Cu²⁺, Zn²⁺] Statement II: Th⁴⁺ is the strongest reducing agent among Th⁴⁺, Ce⁴⁺, Gd³⁺ and Eu²⁺.

Given below are two statements: Statement I: The number of pairs, from the following, in which both the ions are coloured in aqueous solution is 3. [Sc3+, Ti3+], [Mn2+, Cr2+], [Cu2+, Zn2+] Statement II: Th4+ is the strongest reducing agent among Th4+, Ce4+, Gd3+ and Eu2+

Q. Given below are two statements:

Statement I: The number of pairs, from the following, in which both the ions are coloured in aqueous solution is 3.
[Sc³⁺, Ti³⁺], [Mn²⁺, Cr²⁺], [Cu²⁺, Zn²⁺]

Statement II: Th⁴⁺ is the strongest reducing agent among Th⁴⁺, Ce⁴⁺, Gd³⁺ and Eu²⁺.

In the light of the above statements, choose the correct answer from the options given below.

(A) Statement I is false but Statement II is true

(B) Both Statement I and Statement II are false

(D) Statement I is true but Statement II is false

Correct Answer: Both Statement I and Statement II are false

Explanation

An ion shows colour in aqueous solution only if it has partially filled d-orbitals.

Sc³⁺ has d⁰ configuration and is colourless, while Ti³⁺ (d¹) is coloured. Hence the first pair does not have both ions coloured.

Mn²⁺ (d⁵) and Cr²⁺ (d⁴) are both coloured in aqueous solution.

Cu²⁺ (d⁹) is coloured but Zn²⁺ has d¹⁰ configuration and is colourless.

Thus, only one pair has both ions coloured, not three. Hence Statement I is false.

Among the given species, Eu²⁺ is the strongest reducing agent due to its tendency to get oxidised to the more stable Eu³⁺ (half-filled f⁷ configuration).

Th⁴⁺ is not a reducing agent. Hence Statement II is also false.

Explanation

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