d and f-Block Elements Test - 10

In metal carbonyls, the central metal atom is in zero oxidation state.

Zn²⁺ has stable 3d¹⁰, 4s⁰ configuration and Sc³⁺ has a stable configuration of Ar. Hence, they form compounds in these oxidation states.

Mn²⁺ has a stable configuration of half-filled d-orbitals and therefore Mn³⁺ is readily reduced to Mn²⁺.
Hence, the option (2) is correct because Mn⁺³ is a good oxidising agent.
This is also evident from the high value of the reduction potential.
The other options are incorect.
Cr⁺³ has a stable configuration due to half filled t₂g orbitals and is more stable than Cr⁺².
Hence, Cr⁺² can be easily oxidised to Cr⁺³ and it is a good reducing agent.

The elements of groups 8, 9 and 10 resemble horizontally in their properties and are studied together as triads.

Copper, silver and gold are known as coinage metals because they were used to make coins. All these metals are chemically less reactive and are referred to as noble metals. They belong to group 11 of the periodic table.

Mercury has a high value of ionization energy because of fully-filled orbitals, and the electrons are less delocalized, which weakens the metallic bond.

The ligand causes d-d splitting and the salt appears coloured due to d-d transitions of the electrons.

Only V⁴⁺ has one d electron and will show d-d transition.
Sc³⁺ has empty d-orbitals.
Cu⁺ and Zn²⁺ have fully-filled d-orbitals.

This property allows the adsorption of reactant molecules on their surfaces. Hence, they act as catalysts.