Coordination Compounds Test - 3

Optical isomers have mirror images that cannot be superimposed on one another. These are called as enantiomers. The molecules or ions that cannot be superimposed are called chiral.

Octahedral complexes of formula [Ma₄b₂] in which the two ligands b may be oriented cis or trans to each other, e.g.

Geometrical isomers (cis and trans) of [Co(NH₃)₄CI₂]⁺.

Ligand which can ligate through two different atoms is called ambidentate ligand. NO₂^- ion can coordinate either through nitrogen or through oxygen to a central metal atom/ion.

Hence, ligand show linkage isomerism, e.g. the complex [Co(NH₃)₅(NO₂)]CI₂ which is obtained as the red form, in which the nitrite ligand is bound through oxygen (—ONO) and as the yellow form, in which the nitrite ligand is bound through nitrogen (— NO₂). 

The complex [Co(NH₃)₄Br₂]CI show geometrical and ionisation isomerism.

Due to symmetry in the complex [Co(NH₃)₃CI₃], it failed to show optical isomerism. The type of coordination entity show fac and mer isomerism or geometrical isomerism.

The facial (fac) and meridional (mer) isomers of [Co(NH₃)₃CI₃]. 

Ionisation isomerism is due to the exchange of groups between the complex ion and the ions outside it, e.g. [Cr(H₂O)₄CI(NO₂)CI] and [Cr(H₂O)₄CI₂]NO₂ show ionisation isomerism. 

[CoNH₃CI₃] do not exhibit optical isomerism. Optical isomerism is shown by M(AA)₂X₂ type, M(AA)₃ type , [M(AA) B₂X₂] type complexes containing hexadentate ligand and ML_a L_b L_c L_d Left type.

Coordination isomerism is possible when both positive and negative ions of a salt are complex ions and two isomers differ in distribution of ligands in the cation and the anion.

All the three compounds, i.e. [PtCI₂(NH₃)₂], [PdCl₂Brl] and [Pt(NH₃)(py)(CI)(Br)] exhibit cis and trans isomerism.

cis platin is used as ananticancer drug.

Number of hybrid orbitals formed is equal to number of atomic orbitals involved in hybridisation. π bonds will be formed always by pure orbitals (p or d orbitals). Hybrid orbitals arrange around the centre of atom gymmetrically depending on number of bond pairs and lone pairs.

Transition metals are coloured due to the d-d electronic transition.
It's a transition where an electron jumps from one d orbital to another. Normally these are degenerate (the d orbitals have the same energy), but under some conditions, such as the presense of ligands, the degeneracy can be removed so that there is a specific energy (and therefore wavelength) associated with these transitions. These sorts of transitions sometimes have energies located in the visible band, and it's one reason transition metal ions (and complex ions in particular) tend to be highly colored.

Ziegler-Natta catalyst is triethylaluminium Al(C_2​H₅​)₃​ along with TiCl_4​.

Hence, option D is correct.

The correct IUPAC name of Mn₃​(CO)₁₂​ is dodecacarbonyltrimanganese(0). The central metal atom is a cobalt atom in zero oxidation state. The oxidation state is written in parenthesis. Three such Mn atoms are present. Hence, the prefix tri is used. 12 carbonyl groups are present. Hence, the prefix dodeca is used.

Hint:− Mixing of different energy orbitals to form new equal energy orbitals known as hybridization.

Explanation−

∙ Hybridization is the concept of mixing atomic orbitals to form new hybrid orbitals.

∙ Atomic orbitals with similar energy combine to give degenerated hybrid orbitals. 

∙ The number of combining atomic orbitals is equal to the hybridised orbitals. 

∙ They involve redistribution of electrons of combined atomic orbital to hybrid orbitals.

Conclusion− Hence, option B is correct.

For O.S:

X + 0 + 2(-1) = 1

X = 3

Coordination number is the number of molecules linked to the central atom.

Hence B is the correct answer.

Structure (a) = structure (c) and, structure (b) = structure (d)

[Co(NH₃)₄CI₂]⁺ exhibits geometrical isomerism.
cis-[Co(en)₂CI₂]⁺ because of the absence of symmetry elements exhibit optical isomerism.
[Co(NH₃)₅(NO₂)]CI₂ because of the presence of ambidentate (NO₂) ligand exhibit linkage isomerism. [Co(NH₃)₆][Cr(CN₎6] exhibits coordination isomerism because here, cation and anion both are complex.

(i) → (s), (ii) →(p), (iii) → (t), (iv) → (r)

(i) → (r,s), (ii) → (p,q,t), (iii) → (p,q,t), (iv) → (r,s)

since 'd' block elements have higher oxidation states and variable oxidation states and their tendency to form co-ordinate bonds due to presence of unpaired electrons, they form co-ordination complexes

The above complex Na₃[Co (ONO)₆] has two ions: Na⁺ and a complex ion which is negatively charged [Co(ONO)₆]³⁻

According to the rules, name of the positive ion comes first (i.e., sodium), do not mention the number of sodium as it is not present in a square bracket. 

After naming the positive ion, next will be the negative ion, Now in this example, the negative ion is a complex compound, which contain's 'metal' and 'ligand'. While naming a complex, name of ligand comes first, also mention the number of ligand by using prefix (di, tri, tetra. etc..) and if a bidentate ligand is present then mention the atom which is attached to central metal (i.e., hexanitrito −O−) followed by name of metal with the ending 'ate' (i.e., cobaltate, always use the word 'ate' if the complex is negatively charge) and than oxidation number of metal. 

To show the oxidation state, we use Roman numerals inside parenthesis.

Option B is correct.

Only 'Potassium ferrocyanide' (i.e. [Fe(CN)₅​] ) shows properties of coordination compound. 

When it gets dissolve they do not form simple ion like Fe⁺² or CN⁻ , but instead their complex ions remain intact. 

whereas carnallite (i.e. KMgCl₃), Gypsum (i.e. CaSO₄​) and Ferrous  ammonium sulphate (i.e. (NH₄​)₂​Fe(SO₄​)₂​) they dissovle and give simple ions.

Option C is correct.

The primary or principal valency; this is the ionisable valency. 

A metal always gives electron and becomes positively charged that can be neutralized by bonding with negative ion only. In a coordination compound, the number of negative ions needed to satisfy the charge on the central metal ion is it's  primary valency.

MX₆ and MX₅L type complexes do not exhibit geometrical isomerism, cis [Co(en)₂CI₂]⁺ because of the absence of symmetry elements exhibit optical isomerism.
[Co(NH₃)₅(NO₂)]CI₂ because of the presence of ambidentate (NO₂) ligand exhibit linkage isomerism. [CoNH₃)₆][Cr(CN)₆] exhibits coordination isomerism because here cation and anion both are complex.