Question

how will u account for the following?

a. metal-metal bonding is more extensive in the 4d and 5d series if transition elements than the 3d series.


b. Mn(III) undergoes disproportionation reaction easily.


c. Co(II) is easily oxidised in the presence of strong ligand.


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Answer 1

a) in 4d and 5d series valence electron are not that strongly bonded so they are available for metal metal bonding.

b)because it is unstable in solution.

c)because of crystal field stabilisation energy.

Answer 2

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step-by-step explanation:

(a) It is because less energy is required for more number of electrons to take part in metal- metal bonding, as there is smaller difference in the energies of (n-1)d and ns orbital of 4d and 5d series.



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(b) In +3 state, Mn is unstable. It is intermediate oxidation State, so it gets reduced to more stable ${Mn}^{2+}$ and oxidized to another more stable higher oxidation state like ${Mn}^{7+}$.


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(c) In ${Co}^{2+}$, electronic configuration being $3{d}^{7}$, there is one unpaired electron even after pairing in the presence of a strong ligand.

Hence, ${Co}^{2+}$ is oxidized to more stable ${Co}^{3+}$.

Note:-

Refer to the attachments for orbitals filling.

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