Q14 of 26 Page 1

(i) What type of isomerism is shown by the complex [Cr(H2O)6]Cl3?

(ii) On the basis of crystal field theory, write the electronic configuration for d4 ion if Δo > P.


(iii) Write the hybridization and shape of [CoF6]3.


(Atomic number of Co = 27).


(i) The complex [Cr(H2O)6]Cl3 shows hydration isomerism as one of the ligands involved is a water molecule.

[Cr(H2O)5Cl]Cl2(H2O); [Cr(H2O)4Cl2].2H2O are the isomers.


(ii) In a complex, The crystal field splitting Δo depends on the field produced by the ligand and the charge on the metal ion. The pairing energy P represents the energy required for electron pairing in a single orbital. For a d4 ion where Δo > electronic configuration is because it becomes more energetically favourable for the fourth electron to occupy a t2g orbital with this configuration.


(iii) [CoF6]3- : The hybridization is sp3d2 and the shape is octahedral.


Electronic configuration of Co3+ is as below;



As we can see that in 3d shell, 4 orbitals have unpaired electron and other s& p orbitals are vacant.


[CoF6]3- has four unpaired electrons. Thus the compound is paramagnetic.


More from this chapter

All 26 →
12

(i) Name the method of refining to obtain silicon of high purity.

(ii) What is the role of SiO2 in the extraction of copper?


(iii) What is the role of depressants in froth floatation process?


 13

(i) Which one of the following is a polysaccharide :

Starch, maltose, fructose, glucose.


(ii) Write one difference between α-helix and β-pleated sheet structures of protein.


(iii) Write the name of the disease caused by the deficiency of vitamin B12


 15

How can the following conversion be carried out:

(i) Aniline to bromobenzene


(ii) Chlorobenzene to 2-chloroacetophenone


(iii) Chloroethane to butane.


OR


What happens when


(i) chlorobenzene is treated with Cl2/FeCl3.


(ii) Ethyl choride is treated with AgNO2.


(iii) 2-bromopentane is treated with alcoholic KOH?


Write the chemical equations in support of your answer.


 16

Examine the given defective crystal:

Answer the following questions:


(i) Is the above defect stoichiometric or non-stoichiometric?


(ii) Write the term used for this type of defect. Give an example of the compound which shows this type of defect.


(iii) How does this defect affect the density of the crystal?