Given below are two statements : Statement I: Both [Co (NH_3 ) 6 ]^ 3+ and [CoF_6 ]^3 complexes are octahedral but differ in their magnetic behaviour. Statement II: [Co (NH_3 ) ]^ 3+ is diamagnetic whereas [CoF F_6 ]^ 3- is paramagnetic. In the light of the above statements, choose the correct answer from the options given below:

Given below are two statements : Statement I: Both [Co (NH_3 ) 6 …

MCQ

Given below are two statements :

Statement I: Both $\left[\mathrm{Co}\left(\mathrm{NH}_3\right) 6\right]^{3+}$ and $\left[\mathrm{CoF}_6\right]^3$ complexes are octahedral but differ in their magnetic behaviour.

Statement II: $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)\right]^{3+}$ is diamagnetic whereas $\left[\mathrm{CoF} \mathrm{F}_6\right]^{3-}$ is paramagnetic.

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

A
Both Statement $I$ and Statement $II$ are false
B
Statement $I$ is true but Statement $II$ is false
C
Statement $I$ is false but Statement $II$ is true
✓
Both Statement $I$ and Statement $II$ are true

✓

Answer

Correct option: D.

Both Statement $I$ and Statement $II$ are true

d
In $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}, \mathrm{Co}^{3+}$ ion is having $3 \mathrm{~d}^6$ configuration.

Electronic configuration of $\mathrm{Co}^{3+}$ $Image$

In presence of $\mathrm{NH}_3$ ligand, pairing of electrons takes place and it becomes diamagnetic complex ion.

In presence of $\mathrm{NH}_3$ ligand $Image$

$\therefore \quad\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$ is octahedral with $\mathrm{d}^2 \mathrm{sp}^3$ hybridisation and it is diamagnetic in nature.

In case of $\left[\mathrm{CoF}_6\right]^{3-}, \mathrm{Co}$ is in +3 oxidation state and it is having $3 \mathrm{~d}^6$ configuration.

In presence of weak field $\mathrm{F}^{-}$ligand, pairing does not take place.

In presence of $\mathrm{F}^{-}$ligands $Image$

$\therefore \quad \operatorname{In}\left[\mathrm{CoF}_6\right]^{3-}, \mathrm{Co}^{3+}$ is $\mathrm{sp}^3 \mathrm{~d}^2$ hybridised with four unpaired electrons, so it is paramagnetic in nature.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

NEET STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Coinage metals are present in

→

$K_2HgI_4$ is $40\%$ ionized in aqueous solution. The value of its van’t Hoff factor $(i)$

→

Which molecule is $sp^2$ hybridised ?

→

Which one of the following nitro-compounds does not react with nitrous acid ?

→

Match list $- I$ and List $- II.$

	List $-I$		List $-II$
$(a)$	$\begin{array}{*{20}{c}} {O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ {\|\|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ {R - C - Cl \to R - CHO} \end{array}$	$(i)$	$Br _{2} / NaOH$
$(b)$	$\begin{array}{*{20}{c}} {R - C{H_2} - COOH \to R - CH - COOH} \\ {\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\|} \\ {\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,Cl} \end{array}$	$(ii)$	$H _{2} / Pd - BaSO _{4}$
$(c)$	$\begin{array}{*{20}{c}} {O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ {\|\|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ {R - C - N{H_2} \to R - N{H_2}} \end{array}$	$(iii)$	$Zn ( Hg ) /$ Conc. $HCl$
$(d)$	$\begin{array}{*{20}{c}} {O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ {\|\|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ {R - C - C{H_3} \to R - C{H_2} - C{H_3}} \end{array}$	$(iv)$	$Cl _{2}$ / Red $P , H _{2} O$