Coordination compounds. Valence bond theory : tests = Комплексные соединения. Теория валентных связей : тесты

The Ministry of Education and Science of the Russian Federation 
Kazan National Research Technological University 
 
 
 
 
 
 
 
 
 
 
COORDINATION COMPOUNDS.  
VALENS BOND THEORY 
 
Tests 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Kazan 
KNRTU Press 
2018 
 

UDC 546; 54-386

 
The study guide is published in accordance with the decision  
of the Faculty of Chemical Technologies 
 
 
Reviewers: 
Ph. D. (in chemistry), Full Prof. N. B. Berezin 
Ph. D. (in chemistry), Full Prof. M. B. Gazizov 
 
Contributors: 
Assoc. Prof. М. М. Petrova 
Full Prof. Е. М. Zueva 
Full Prof. А. М. Kuznetsov 
 
 
 
 
 

Coordination compounds. Valence bond theory : tests / сontributors:
M. M. Petrova, E. M. Zueva, A. M. Kuznetsov; The Ministry of Education 
and Science of the Russian Federation, Kazan National Research 
Technological University. – Kazan : KNRTU Press, 2018. – 52 p.

 
The study guide contains individual test tasks, which can be used to control 
student achievements in the topic "Coordination compounds. Valence bond 
theory".  
The tasks are developed for the first-year students of engineering degree 
programs, who study the discipline "General and Inorganic Chemistry" and "The 
additional chapters of Inorganic Chemistry" in English.  
The study guide was prepared at the Department of Inorganic Chemistry. 
 
 

 
 
 
 
 

UDC 546; 54-386

INDIVIDUAL TASKS 
 
Variant 1 
Task 1 
1. The chemical formula of  tetraamminezinc(II) chloride is  
А) [Zn(NH3)3]Cl2; 
B) [Zn(NH3)2]Cl2;

C) [Zn(NH3)]Cl2;
D) [Zn(NH3)4]Cl2.

 
2. The [Co(CN)6]3− complex is called 
А) hexacyanocobaltate(III) ion;
B) hexacyanocobaltate(II) ion;

C) hexacyanocobalt(III) ion;
D) hexacyanocobalt(II) ion.

 
3. The compound containing a cationic complex is  
А) [Pt(NH3)2Cl2]; 
B) K3[Fe(CN)6];

C) Na[Al(OH)4];
D) [Co(H2O)6]Cl2.

   
4. In the [Co(CN)6]3− complex, the coordination number and the charge of 
coordination center are equal to  
А) 3, +6;
B) 6, +3;

C) 6, −3;
D) 3, −6.

 
5. In the [Co(NH3)5Cl]Cl2 compound, the ligands are  
А) chloride ions;
B) cobalt ions;

C) water molecules;
D) ammonia molecules.

6. Specify the products of the chemical reaction Al2(SO4)3 + KOHexcess →  
А) Al(OH)3;
B) K2SO4;

C) K3[Al(OH)6];
D) [Al(H2O)6]2(SO4)3.

7. The expression for the overall instability constant of the [Ag(NH3)2]+ 
complex is  
А) [Ag(NH3)2

+]/[Ag+][NH3]2;
B) [Ag+][NH3]/[Ag(NH3)2

+];

C) [Ag+][2NH3]/[Ag(NH3)2

+];
D) [Ag+][NH3]2/[Ag(NH3)2

+].

8. According to the values of the overall stability constants (see Appendix), 
the most stable complex is 
А) [Cd(NH3)4]2+;
B) [Fe(CN)6]3−;

C) [Al(OH)4]−;
D) [HgCl4]2−.

Task 2. Determine the coordination geometry of the diamagnetic 
[Pt(NH3)4]2+complex. 
1. Specify the valence electron configuration of the coordination center in 
this complex. 
А) 6s2;
B) 5d8;

C) 5d86s2;
D) 5d10.

2. The number of unpaired electrons located on the coordination center is 
А) 8;
B) 10;

C) 2;
D) 0.

3. The orbital hybridization type of the coordination center is  
А) d2sp3;
B) sp3;

C) sp;
D) dsp2.

4. What is the coordination geometry of this complex? 
А) linear;
B) square planar;

C) tetrahedral;
D) octahedral.

 
 
Variant 2 
Task 1 
1. The chemical formula of  potassium hexacyanoferrate(III) is  
А) K3[Fe(CN)6]; 
B) K4[Fe(CN)6];

C) K[Fe(CN)4];
D) Na[Fe(NCS)4].

 
2. The [Ag(NH3)2]+ complex is called  
А) ion diammineargentat(I);
B) ion diammineargentat(II);

C) ion diamminesilver(II);
D) ion diamminesilver(I).

 
3. The compound containing an anionic complex is   
А) [Pt(NH3)2Cl2]; 
B) [Ti(H2O)6]Cl3;

C) [Ni(NH3)6]SO4;
D) K3[FeF6].

   
4. In the [Ag(NH3)2]+ complex, the coordination number and the charge of 
coordination center are equal to  
А) 2, +1;
B) 1, +1;

C) 2, +3;
D) 3, +1.

 

5. In the K3[Ag(S2O3)2]  compound, the ligands are   
А) thiosulphate ions;
B) silver ions;

C) sulfide ions; 
D) potassium ions.

6. Specify the products of the chemical reaction Cr(OH)3 + HCl + Н2О → 
А) Cr(OH)2Cl; 
B) CrOHCl2;

C) the reaction does not proceed;
D) [Cr(H2O)6]Cl3.

7. The expression for the overall stability constant of the [Co(CN)6]3− 
complex is  
А) [Co(CN)6] 3−]/[Co3+][CN−]6;
B) [Co3+][CN−]/[[Co(CN)6] 3−];

C) [Co(CN)6] 3−]/[Co3+][6CN−];
D) [Co3+][CN−]6/[Co(CN)6] 3−].

8. According to the values of the overall stability constants (see Appendix), 
the least stable complex is 
А) [Cd(NH3)4]2+;
B) [Fe(CN)6]3−;

C) [Al(OH)4]−;
D) [HgCl4]2−.

 
Task 2  
Determine the coordination geometry of [Ti(H2O)6]3+ complex. 
1. Specify the valence electron configuration of the coordination center in 
this complex. 
А) 4s2;
B) 3d04s1;

C) 3d24s2;
D) 3d1.

2. The number of unpaired electrons located on the coordination center is 
А) 1;
B) 4;

C) 2;
D) 0.

3. The orbital hybridization type of the coordination center is  
А) d2sp3;
B) sp3;

C) sp;
D) dsp2.

4. What is the coordination geometry of this complex? 
А) linear;
B) square planar;

C) tetrahedral;
D) octahedral.
 
 

Variant 3 
Task 1 
1. The chemical formula of  hexaaquatitanium(III) chloride is  
А) [Ti(H2O)4]Cl3;
B) [Ti(H2O)6]Cl4;

C) [Ti(H2O)6]Cl3;
D) [Ti(H2O)4]Cl4.

 
2. The [Cr(OH)4]− complex is called  
А) tetrahydrochromium(I) ion;
B) tetrahydroxochromate(III) ion;

C) tetrahydrochromate(IV) ion;
D) tetrahydrochromium(III) ion.

 
3. The compound containing a cationic complex is   
А) [Pt(NH3)2Cl2]; 
B) [Cd(NH3)4]Cl2;

C) K[Cr(OH)4];
D) Na2[Ni(CN)4].

   
4. In the [Cr(OH)4]− complex, the coordination number and the charge of 
coordination center are equal to  
А) 4, +3;
B) 1, +3;

C) 4, −1;
D) 4, −4.

 
5. In the K[Cr(OH)4] compound, the ligands are   
А) hydroxide ions;
B) chromium ions;

C) water molecules;
D) potassium ions.

6. Specify the products of the chemical reaction CrCl3 + KOHexcess → 
А) K3[Cr(OH)6];
B) KCl;

C) Cr(OH)3;
D) [Cr(H2O)6]Cl3.

7. The expression for the overall instability constant of the [Cr(OH)4]− 

complex is  
А) [Cr(OH)4

−]/[Cr3+][OH−]4;
B) [Cr(OH)4

−]/[Cr3+][4OH−];

C) [Cr3+][OH−]4/[Cr(OH)4

−];
D) [Cr3+][OH−]/[Cr(OH)4

−].

8. According to the values of the overall stability constants (see Appendix), 
the most stable complex is  
А) [Co(NH3)6]3+;
B) [HgBr4]2−;

C) [AuBr2]−;
D) [CdI4]2−.

   

Task 2. Determine the coordination geometry of [Cr(OH)6]3− complex. 

1. Specify the valence electron configuration of the coordination center in 
this complex. 
А) 4s2;
B) 3d3;

C) 3d44s2;
D) 3d14s2.

2. The number of unpaired electrons located on the coordination center is 
А) 3;
B) 6;

C) 2;
D) 0.

3. The orbital hybridization type of the coordination center is 
А) d2sp3;
B) sp3;

C) sp;
D) dsp2.

4. What is the coordination geometry of this complex? 
А) linear;
B) square planar;

C) tetrahedral;
D) octahedral.
 
 
Variant 4 
Task 1 
1. The chemical formula of potassium tetraiodohydrargyrate(II) is  
А) K3[HgI4];
B) K2[HgI4];

C) K2[HgI6];
D) Na2[HgI4].

 
2. The [Zn(NH3)4]2+ complex is called  
А) diamminezincate(II) ion;
B) tetraamminezinc(II) ion;

C) tetraamminezincate(II) ion;
D) diamminezinc(II) ion.

 
3. The compound containing a neutral complex is  
А) [Pt(NH3)2Cl2]; 
B) Na3[Co(CN)6];

C) K[Ag(NH3)2];
D) Na[Au(NH3)2].

   
4. In the [Zn(NH3)4]2+ complex, the coordination number and the charge of 
coordination center are equal to  
А) 2, +4;
B) 2, +2;

C) 4, +4;
D) 4, +2.

 

5. In the [Zn(NH3)4](NO3)2 compound, the ligands are  
А) nitrate ions;
B) ammonium cations;

C) nitrite ions; 
D) ammonia molecules.

6. Specify the products of the chemical reaction Al(OH)3 + HCl + Н2О → 
А) Al(OH)2Cl; 
B) AlOHCl2;

C) the reaction does not proceed;
D) [Al(H2O)6]Cl3.

7. The expression for the overall stability constant of the [Co(NCS)4]2− 
complex is  
А) [Co(NCS)4

2−]/[Co2+][NCS−]4;
B) [Co2+][NCS−]/[Co(NCS)4

2−];

C) [Co(NCS)4

2−]/[Co2+][4NCS−];
D) [Co2+][NCS−]4/[Co(NCS)4

2−].

8. According to the values of the overall stability constants (see Appendix), 
the least stable complex is  
А) [Co(NH3)6]3+;
B) [HgBr4]2−;

C) [CdBr4]2−;
D) [CdI4]2−.

  
 Task 2. Determine the coordination geometry of the paramagnetic 
[NiCl4]2− complex.  
1. Specify the valence electron configuration of the coordination center in 
this complex. 
А) 4s2;
B) 3d64s2;

C) 3d84s2;
D) 3d8.

2. The number of unpaired electrons located on the coordination center is  
А) 1;
B) 4;

C) 2;
D) 0.

3. The orbital hybridization type of the coordination center is 
А) d2sp3;
B) sp3;

C) sp;
D) dsp2.

4. What is the coordination geometry of this complex?  
А) linear;
B) square planar;

C) tetrahedral;
D) octahedral.
 
 
 

Variant 5 
Task 1  
1. The chemical formula of tetraamminezinc(II) sulfate is  
А) [Zn(NH3)4]SO3; 
B) [Zn(NH3)4]SO4;

C) [Zn(NH3)3]SO4;
D) [Zn(NH3)6]SO4.

 
2. The [PbI4]2− complex is called  
А) tetraiodidelead(II) ion;
B) tetraiodolead(II) ion;

C) tetraiodoplumbate(II) ion;
D) tetraiodideplumbate(II) ion.

 
3. The compound containing a cationic complex is  
А) [Pt(NH3)2Cl2]; 
B) K3[FeF6];

C) [Co(H2O)6]Cl2;
D) Na3[Co(CN)6].

   

4. In the [PbI4]2− complex, the coordination number and the charge of 
coordination center are equal to  
А) 4, +2;
B) 2, +3;

C) 4, −2;
D) 4, −4.

 
5. In the K2[PbI4] compound, the ligands are  
А) iodide ions;
B) lead ion;

C) iodine molecules;
D) potassium ions.

6. Specify the products of the chemical reaction ZnSO4 + NaOHexcess → 
А) Na3[Zn(OH)6];
B) Na2SO4;

C) Zn(OH)2;
D) [Zn(H2O)6]SO4.

7. The expression for the overall instability constant of the [PbI4]2− complex is  
А) [PbI4

2−]/[Pb2+][I−]4;
B) [PbI4

2−]/[Pb2+][4I−];

C) [Pb2+][I−]/[PbI4

2−];
D) [Pb2+][I−]4/[PbI4

2−].

8. According to the values of the overall stability constants (see Appendix), 
the most stable complex is  
А) [ZnBr4]2−;
B) [Co(CN)6]3−;

C) [FeF6]3−;
D [Cd(NH3)4]2+.

Task 2. Determine the coordination geometry of the diamagnetic 
[Cu(NH3)2]+ complex.  

1. Specify the valence electron configuration of the coordination center in 
this complex 
А) 4s1;
B) 3d10;

C) 3d104s1;
D) 3d94s2.

2. The number of unpaired electrons located on the coordination center is 
А) 3;
B) 6;

C) 2;
D) 0.

3. The orbital hybridization type of the coordination center is 
А) d2sp3;
B) sp3;

C) sp;
D) dsp2.

4. What is the coordination geometry of this complex?  
А) linear;
B) square planar;

C) tetrahedral;
D) octahedral.

 
Variant 6 
Task 1  
1. The chemical formula of sodium tetrahyroxozincate(II) is  
А) Na4[Zn(OH)6];
B) Na4[Zn(OH)4];

C) Na2[Zn(OH)4];
D) Na[Zn(OH)4].

 
2. The [Cr(H2O)6]3+ complex is called  
А) hexahydroxochromate(III) ion;
B) hexahydroxochromium(III) ion;

C) hexaaquachromate(III) ion;
D) hexaaquachromium(III) ion.

 
3. The compound containing an anionic complex is   
А) [Pt(NH3)2Cl2]; 
B) [Cd(NH3)4]Cl2;

C) Na[Al(OH)4];
D) [Co(H2O)6]Cl2.

   
4. In the [Cr(H2O)6]3+ complex, the coordination number and the charge of 
coordination center are equal to  
А) 3, +6;
B) 3, +3;

C) 6, +3;
D) 6, −3.