Difference between revisions of "Coordination chemistry questions"

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1) The number of possible isomers of [Ru(PPh<sub>3</sub>)<sub>2</sub>(acac)<sub>2</sub>] (acac=acetylacetonate) is
+
1) The number of possible [[isomers]] of [Ru(PPh<sub>3</sub>)<sub>2</sub>(acac)<sub>2</sub>] (acac=[[acetylacetonate]]) is
 
:a) 2
 
:a) 2
 
:b) 3
 
:b) 3
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2) The correct spinel structure of Co3O4 is
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2) The correct [[spinel structure]] of Co3O4 is
 
:a) (Co<sup>2+</sup>)<sub>t</sub>(2Co<sup>3+</sup>)<sub>o</sub>O<sub>4</sub>;
 
:a) (Co<sup>2+</sup>)<sub>t</sub>(2Co<sup>3+</sup>)<sub>o</sub>O<sub>4</sub>;
 
:b) (Co<sup>2+</sup>)<sub>t</sub>(2Co<sup>3+</sup>Co<sup>3+</sup>)<sub>o</sub>O<sup>4</sup>;
 
:b) (Co<sup>2+</sup>)<sub>t</sub>(2Co<sup>3+</sup>Co<sup>3+</sup>)<sub>o</sub>O<sup>4</sup>;
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:d) (2Co<sup>3+</sup>)<sub>t</sub>(Co<sup>2+</sup>)<sub>o</sub>O<sub>4</sub>
 
:d) (2Co<sup>3+</sup>)<sub>t</sub>(Co<sup>2+</sup>)<sub>o</sub>O<sub>4</sub>
 
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3) In the solid state, the [CuCl<sub>5</sub>]<sup>3-</sup> ion has two types of bonds. These are;
+
3) In the [[solid state]], the [CuCl<sub>5</sub>]<sup>3-</sup> ion has two types of bonds. These are;
 
:a) Three long and two short;  
 
:a) Three long and two short;  
 
:b) Two long and three short;  
 
:b) Two long and three short;  
 
:c) One long and four short and  
 
:c) One long and four short and  
 
:d) Four long and one short
 
:d) Four long and one short
4) The platinum complex of NH<sub>3</sub> and Cl<sup>–</sup> ligands is an anti-tumour agent. The correct isomeric formula of the complex and its precursor are:
+
4) The [[platinum complex]] of NH<sub>3</sub> and Cl<sup>–</sup> ligands is an [[anti tumour agent]]. The correct isomeric formula of the complex and its precursor are:
 
:a) cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub> and PtCl<sub>4</sub><sup>2-</sup>;  
 
:a) cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub> and PtCl<sub>4</sub><sup>2-</sup>;  
 
:b) trans-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub> and PtCl<sub>4</sub><sup>2-</sup>;  
 
:b) trans-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub> and PtCl<sub>4</sub><sup>2-</sup>;  
 
:c) cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub> and Pt(NH<sub>3</sub>)<sub>4</sub><sup>2+</sup>  
 
:c) cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub> and Pt(NH<sub>3</sub>)<sub>4</sub><sup>2+</sup>  
 
:d) trans-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub> and Pt(NH<sub>3</sub>)<sub>4</sub><sup>2+</sup>
 
:d) trans-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub> and Pt(NH<sub>3</sub>)<sub>4</sub><sup>2+</sup>
5) The δ-bond is formed via the overlap of;
+
5) The δ -bond is formed via the overlap of;
 
:a) dx<sup>2</sup>-y<sup>2</sup> and dx<sup>2</sup>-y<sup>2</sup> orbitals;  
 
:a) dx<sup>2</sup>-y<sup>2</sup> and dx<sup>2</sup>-y<sup>2</sup> orbitals;  
 
:b) dxz and dxz orbitals;  
 
:b) dxz and dxz orbitals;  
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:'''Answer: +b) 3
 
:'''Answer: +b) 3
 
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'''Explanation''' [[File:Structure of isomers.png|thumb|90px]]This is an example for an octahedral complex of the type MA<sub>2</sub>B<sub>2</sub> (A: monodentate ligand, while B: a bidentate ligand). The possibility of having this in different structures is three;  
+
'''Explanation''' [[File:Structure of isomers.png|thumb|90px]]This is an example for an octahedral complex of the type MA<sub>2</sub>B<sub>2</sub> (A: [[monodentate ligand]], while B: a [[bidentate ligand]]). The possibility of having this in different structures is three;  
 
* having A above and below the plane,  
 
* having A above and below the plane,  
 
* two mirror images of two A adjacent to each other in a same plane two acac in and above/below the plane.
 
* two mirror images of two A adjacent to each other in a same plane two acac in and above/below the plane.
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2) The correct spinel structure of Co3O4 is
 
2) The correct spinel structure of Co3O4 is
 
:'''Answer''': +a) (Co<sup>2+</sup>)<sub>t</sub>(2Co<sup>3+</sup>)<sub>o</sub>O<sub>4</sub>;
 
:'''Answer''': +a) (Co<sup>2+</sup>)<sub>t</sub>(2Co<sup>3+</sup>)<sub>o</sub>O<sub>4</sub>;
'''Explanation''': Co3O4 is an example for a normal spinel, which possess Co2+ and Co3+ to be occupied by the tetrahedral and octahedral oxide ligand fields, respectively. Alongside, there exist one +2 and two 3+ metal centers that can nullify the charge, hence option (a) is correct.
+
'''Explanation''': Co3O4 is an example for a normal spinel, which possess Co2+ and Co3+ to be occupied by the [[tetrahedral]] and [[octahedral]] oxide ligand fields, respectively. Alongside, there exist one +2 and two 3+ metal centers that can nullify the charge, hence option (a) is correct.
 
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3) In the solid state, the [CuCl<sub>5</sub>]<sup>3-</sup> ion has two types of bonds. These are;
 
3) In the solid state, the [CuCl<sub>5</sub>]<sup>3-</sup> ion has two types of bonds. These are;
 
:'''Answer'''a) Three long and two short;  
 
:'''Answer'''a) Three long and two short;  
Explanation: This is an example for a trigonal bipyramidal coordination geometry, in which three donor atoms are in the same plane along with the metal atom, while rest two are above and below. Three ligands in the plane have to repel four electrons of metal that are accommodated in dxy and dx2-y2 orbitals experiencing more amount of repulsion, while along z-axis just one electron in dz2 orbital that opposes two donors along z-axis leading to lesser repulsion. Hence, as per distortion, this complex has three long and two short bonds.   
+
Explanation: This is an example for a [[trigonal bipyramidal coordination geometry]], in which three donor atoms are in the same plane along with the metal atom, while rest two are above and below. Three ligands in the plane have to repel four electrons of metal that are accommodated in dxy and dx<sub>2</sub>-y<sub>2</sub> orbitals experiencing more amount of repulsion, while along z-axis just one electron in dz<sub>2</sub> orbital that opposes two donors along z-axis leading to lesser repulsion. Hence, as per distortion, this complex has three long and two short bonds.   
 
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4) The platinum complex of NH<sub>3</sub> and Cl<sup>–</sup> ligands is an anti-tumour agent. The correct isomeric formula of the complex and its precursor are:
 
4) The platinum complex of NH<sub>3</sub> and Cl<sup>–</sup> ligands is an anti-tumour agent. The correct isomeric formula of the complex and its precursor are:
 
:'''Answer'''a) cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub> and PtCl<sub>4</sub><sup>2-</sup>;  
 
:'''Answer'''a) cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub> and PtCl<sub>4</sub><sup>2-</sup>;  
Explanation: It is well known that cis-platin is the antitumour agent that has been presently being used to treat several types of human derived tumours, therefore, options (b) and (d) are wrong. Since the trans effect of chlorido ligand is greater than the ammonia ligand, PtCl42- is the starting material. I.e., successive addition of two moles of ammonia to PtCl42- give rise to cis-platin, while successive addition of two chlorido ligands to Pt(NH3)42+ give rise to trans-platin.  
+
Explanation: It is well known that cis-platin is the antitumour agent that has been presently being used to treat several types of human derived tumours, therefore, options (b) and (d) are wrong. Since the trans effect of chlorido ligand is greater than the ammonia ligand, PtCl42- is the starting material. I.e., successive addition of two moles of ammonia to PtCl42- give rise to cis-platin, while successive addition of two chlorido ligands to Pt(NH<sub>3</sub>)<sub>4</sub><sup>2+</sup> give rise to trans-platin.  
 
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5) The δ-bond is formed via the overlap of;
 
5) The δ-bond is formed via the overlap of;
 
:'''Answer'''a) dx<sup>2</sup>-y<sup>2</sup> and dx<sup>2</sup>-y<sup>2</sup> orbitals;  
 
:'''Answer'''a) dx<sup>2</sup>-y<sup>2</sup> and dx<sup>2</sup>-y<sup>2</sup> orbitals;  
Explanation: A δ-bond is formed via the axial overlapping of orbitals. In this case, the δ-bond formation refers to the bonding that exist between two metal atoms, and dx2-y2 orbitals present on the axes (x and y-axes) so it is feasible to have δ-bond formation by overlapping of dx2-y2 and dx2-y2 orbitals.
+
Explanation: A δ -bond is formed via the axial overlapping of orbitals. In this case, the δ-bond formation refers to the bonding that exist between two metal atoms, and dx2-y2 orbitals present on the axes (x and y-axes) so it is feasible to have δ-bond formation by overlapping of dx<sub>2</sub>-y<sub>2</sub> and dx<sub>2</sub>-y<sub>2</sub> orbitals.

Latest revision as of 09:56, 17 May 2020

Questions:  A0  A1  A2   B0  B1  B2  

Answers:   A0  A1  A2   B0  B1  B2  

ALL A0[edit]

1) The number of possible isomers of [Ru(PPh3)2(acac)2] (acac=acetylacetonate) is

a) 2
b) 3
c) 4
d) 5

2) The correct spinel structure of Co3O4 is

a) (Co2+)t(2Co3+)oO4;
b) (Co2+)t(2Co3+Co3+)oO4;
c) (Co2+ Co3+)t(Co3+)oO4
d) (2Co3+)t(Co2+)oO4

3) In the solid state, the [CuCl5]3- ion has two types of bonds. These are;

a) Three long and two short;
b) Two long and three short;
c) One long and four short and
d) Four long and one short

4) The platinum complex of NH3 and Cl ligands is an anti tumour agent. The correct isomeric formula of the complex and its precursor are:

a) cis-Pt(NH3)2Cl2 and PtCl42-;
b) trans-Pt(NH3)2Cl2 and PtCl42-;
c) cis-Pt(NH3)2Cl2 and Pt(NH3)42+
d) trans-Pt(NH3)2Cl2 and Pt(NH3)42+

5) The δ -bond is formed via the overlap of;

a) dx2-y2 and dx2-y2 orbitals;
b) dxz and dxz orbitals;
c) dxy and dxy orbitals and :
d) dyz and dyz orbitals





Key: A0[edit]

1) The number of possible isomers of [Ru(PPh3)2(acac)2] (acac=acetylacetonate) is

Answer: +b) 3
Explanation This is an example for an octahedral complex of the type MA2B2 (A: monodentate ligand, while B: a bidentate ligand). The possibility of having this in different structures is three;
  • having A above and below the plane,
  • two mirror images of two A adjacent to each other in a same plane two acac in and above/below the plane.

2) The correct spinel structure of Co3O4 is

Answer: +a) (Co2+)t(2Co3+)oO4;

Explanation: Co3O4 is an example for a normal spinel, which possess Co2+ and Co3+ to be occupied by the tetrahedral and octahedral oxide ligand fields, respectively. Alongside, there exist one +2 and two 3+ metal centers that can nullify the charge, hence option (a) is correct.

3) In the solid state, the [CuCl5]3- ion has two types of bonds. These are;

Answera) Three long and two short;

Explanation: This is an example for a trigonal bipyramidal coordination geometry, in which three donor atoms are in the same plane along with the metal atom, while rest two are above and below. Three ligands in the plane have to repel four electrons of metal that are accommodated in dxy and dx2-y2 orbitals experiencing more amount of repulsion, while along z-axis just one electron in dz2 orbital that opposes two donors along z-axis leading to lesser repulsion. Hence, as per distortion, this complex has three long and two short bonds.

4) The platinum complex of NH3 and Cl ligands is an anti-tumour agent. The correct isomeric formula of the complex and its precursor are:

Answera) cis-Pt(NH3)2Cl2 and PtCl42-;

Explanation: It is well known that cis-platin is the antitumour agent that has been presently being used to treat several types of human derived tumours, therefore, options (b) and (d) are wrong. Since the trans effect of chlorido ligand is greater than the ammonia ligand, PtCl42- is the starting material. I.e., successive addition of two moles of ammonia to PtCl42- give rise to cis-platin, while successive addition of two chlorido ligands to Pt(NH3)42+ give rise to trans-platin.

5) The δ-bond is formed via the overlap of;

Answera) dx2-y2 and dx2-y2 orbitals;

Explanation: A δ -bond is formed via the axial overlapping of orbitals. In this case, the δ-bond formation refers to the bonding that exist between two metal atoms, and dx2-y2 orbitals present on the axes (x and y-axes) so it is feasible to have δ-bond formation by overlapping of dx2-y2 and dx2-y2 orbitals.