Find the best tutors and institutes for Class 12 Tuition
Q5.30:
Amongst the following, the most stable complex is
Solution :
Initial Data and Theoretical Foundation
To determine the most stable coordination complex among a series, we must evaluate the Chelate Effect and the nature of the ligands involved. Stability in coordination complexes is defined by the equilibrium constant for the formation of the complex ($K_f$).
The complexes under consideration for comparison typically involve different denticity levels of ligands. A chelate ring formation significantly increases stability compared to monodentate ligands due to a favorable change in entropy ($\Delta S > 0$) [Per the Second Law of Thermodynamics].
Step 1: Analyzing the Chelate Effect
The stability of a complex increases with the number of chelate rings formed. A polydentate ligand (such as ethylenediamine or EDTA) forms more stable complexes than monodentate ligands (such as $NH_3$ or $H_2O$) because the displacement of monodentate ligands by a polydentate ligand increases the number of free particles in the solution, thereby increasing the entropy of the system.
Step 2: Mathematical Justification of Stability
The Gibbs free energy change ($\Delta G^\circ$) for the formation of a complex is given by:
$\Delta G^\circ = \Delta H^\circ - T\Delta S^\circ = -RT \ln K_f$
As the number of chelate rings increases, $\Delta S^\circ$ becomes more positive, leading to a larger negative $\Delta G^\circ$, which corresponds to a significantly larger $K_f$ value [Per the thermodynamic definition of spontaneity].
Step 3: Comparative Analysis
Consider the common set of complexes compared in this academic context:
| Complex | Ligand Type | Number of Rings | Stability Trend |
|---|---|---|---|
| $[Fe(H_2O)_6]^{3+}$ | Monodentate | 0 | Low |
| $[Fe(en)_3]^{3+}$ | Bidentate | 3 | High |
| $[Fe(EDTA)]^{-}$ | Hexadentate | 5 | Very High |
Step 4: Geometric Representation of a Chelate Complex
Final Determination
Amongst typical coordination compounds, the complex with the highest denticity ligand, such as $[Fe(EDTA)]^{-}$ or complexes involving $en$ (ethylenediamine), is the most stable because it forms the maximum number of chelate rings, creating the most pronounced entropic stabilization effect [Per the Chelate Effect Principle].
Final Solution: The most stable complex is the one involving polydentate ligands (specifically those forming the highest number of chelate rings), as it maximizes entropic favorability and thermodynamic stability constant $K_f$.
More Questions from Class 12 Chemistry Coordination Compounds Exercises
- Q5.1: Explain the bonding in coordination compounds in terms of Werner’s postulates.
- Q5.1: Explain the bonding in coordination compounds in terms of Werner’s postulates.
- Q5.10 (i): Draw the structures of optical isomers of: ([Cr(C_{2}O_{4})_{3}]^{3-})
- Q5.10 (ii): Draw the structures of optical isomers of: ([PtCl_{2}(en)_{2}]^{2+})
- Q5.10 (iii): Draw the structures of optical isomers of: ([Cr(NH_{3})_{2}Cl_{2}(en)]^{+})
- Q5.10(i): Draw the structures of optical isomers of: \([Cr(C_{2}O_{4})_{3}]^{3-}\)
- Q5.10(ii): Draw the structures of optical isomers of: \([PtCl_{2}(en)_{2}]^{2+}\)
- Q5.10(iii): Draw the structures of optical isomers of: \([Cr(NH_{3})_{2}Cl_{2}(en)]^{+}\)
- Q5.11 (i): Draw all the isomers (geometrical and optical) of: ([CoCl_{2}(en)_{2}]^{+})
- Q5.11 (ii): Draw all the isomers (geometrical and optical) of: ([Co(NH_{3})Cl(en)_{2}]^{2+})
- Q5.11 (iii): Draw all the isomers (geometrical and optical) of: ([Co(NH_{3})_{2}Cl_{2}(en)]^{+})
- Q5.11(i): Draw all the isomers (geometrical and optical) of: \([CoCl_{2}(en)_{2}]^{+}\)
- Q5.11(ii): Draw all the isomers (geometrical and optical) of: \([Co(NH_{3})Cl(en)_{2}]^{2+}\)
- Q5.11(iii): Draw all the isomers (geometrical and optical) of: \([Co(NH_{3})_{2}Cl_{2}(en)]^{+}\)
- Q5.12: Write all the geometrical isomers of \([Pt(NH_{3})(Br)(Cl)(py)]\) and how many of these will exhibit optical isomers?
- Q5.12: Write all the geometrical isomers of ([Pt(NH_{3})(Br)(Cl)(py)]) and how many of these will exhibit optical isomers?
- Q5.13: Aqueous copper sulphate solution (blue in colour) gives: (i) a green precipitate with aqueous potassium fluoride and (ii) a bright green solution with aqueous potassium chloride. Explain these experimental results.
- Q5.13: Aqueous copper sulphate solution (blue in colour) gives: (i) a green precipitate with aqueous potassium fluoride and (ii) a bright green solution with aqueous potassium chloride. Explain these experimental results.
- Q5.14: What is the coordination entity formed when excess of aqueous \(KCN\) is added to an aqueous solution of copper sulphate? Why is it that no precipitate of copper sulphide is obtained when \(H_{2}S(g)\) is passed through this solution?
- Q5.14: What is the coordination entity formed when excess of aqueous KCN is added to an aqueous solution of copper sulphate? Why is it that no precipitate of copper sulphide is obtained when ((H_{2}S(g))) is passed through this solution?
- Q5.15 (i): Discuss the nature of bonding on the basis of valence bond theory: ([Fe(CN)_{6}]^{4-})
- Q5.15 (ii): Discuss the nature of bonding on the basis of valence bond theory: ([FeF_{6}]^{3-})
- Q5.15 (iii): Discuss the nature of bonding on the basis of valence bond theory: ([Co(C_{2}O_{4})_{3}]^{3-})
- Q5.15 (iv): Discuss the nature of bonding on the basis of valence bond theory: ([CoF_{6}]^{3-})
- Q5.15(i): Discuss the nature of bonding in the following coordination entities on the basis of valence bond theory: \([Fe(CN)_{6}]^{4-}\)
- Q5.15(ii): Discuss the nature of bonding in the following coordination entities on the basis of valence bond theory: \([FeF_{6}]^{3-}\)
- Q5.15(iii): Discuss the nature of bonding in the following coordination entities on the basis of valence bond theory: \([Co(C_{2}O_{4})_{3}]^{3-}\)
- Q5.15(iv): Discuss the nature of bonding in the following coordination entities on the basis of valence bond theory: \([CoF_{6}]^{3-}\)
- Q5.16: Draw figure to show the splitting of d orbitals in an octahedral crystal field.
- Q5.16: Draw figure to show the splitting of d orbitals in an octahedral crystal field.
- Q5.17: What is spectrochemical series? Explain the difference between a weak field ligand and a strong field ligand.
- Q5.17: What is spectrochemical series? Explain the difference between a weak field ligand and a strong field ligand.
- Q5.18: What is crystal field splitting energy? How does the magnitude of \(\Delta_{o}\) decide the actual configuration of d orbitals in a coordination entity?
- Q5.18: What is crystal field splitting energy? How does the magnitude of (\Delta_{o}) decide the actual configuration of d orbitals in a coordination entity?
- Q5.19: \([Cr(NH_{3})_{6}]^{3+}\) is paramagnetic while \([Ni(CN)_{4}]^{2-}\) is diamagnetic. Explain why?
- Q5.19: ([Cr(NH_{3})_{6}]^{3+}) is paramagnetic while ([Ni(CN)_{4}]^{2-}) is diamagnetic. Explain why?
- Q5.2: \(FeSO_{4}\) solution mixed with \((NH_{4})_{2}SO_{4}\) solution in 1:1 molar ratio gives the test of \(Fe^{2+}\) ion but \(CuSO_{4}\) solution mixed with aqueous ammonia in 1:4 molar ratio does not give the test of \(Cu^{2+}\) ion. Explain why?
- Q5.2: ((FeSO_{4})) solution mixed with ((NH_{4})_{2}SO_{4}) solution in 1:1 molar ratio gives the test of ((Fe^{2+})) ion but ((CuSO_{4})) solution mixed with aqueous ammonia in 1:4 molar ratio does not give the test of ((Cu^{2+})) ion. Explain why?
- Q5.20: A solution of \([Ni(H_{2}O)_{6}]^{2+}\) is green but a solution of \([Ni(CN)_{4}]^{2-}\) is colourless. Explain.
- Q5.20: A solution of ([Ni(H_{2}O)_{6}]^{2+}) is green but a solution of ([Ni(CN)_{4}]^{2-}) is colourless. Explain.
- Q5.21: \([Fe(CN)_{6}]^{4-}\) and \([Fe(H_{2}O)_{6}]^{2+}\) are of different colours in dilute solutions. Why?
- Q5.21: ([Fe(CN)_{6}]^{4-}) and ([Fe(H_{2}O)_{6}]^{2+}) are of different colours in dilute solutions. Why?
- Q5.22: Discuss the nature of bonding in metal carbonyls.
- Q5.22: Discuss the nature of bonding in metal carbonyls.
- Q5.23 (i): Give the oxidation state, d orbital occupation and coordination number of the central metal ion: (K_{3}[Co(C_{2}O_{4})_{3}])
- Q5.23 (ii): Give the oxidation state, d orbital occupation and coordination number of the central metal ion: (cis-[CrCl_{2}(en)_{2}]Cl)
- Q5.23 (iii): Give the oxidation state, d orbital occupation and coordination number of the central metal ion: ((NH_{4})_{2}[CoF_{4}])
- Q5.23 (iv): Give the oxidation state, d orbital occupation and coordination number of the central metal ion: ([Mn(H_{2}O)_{6}]SO_{4})
- Q5.23(i): Give the oxidation state, d orbital occupation and coordination number of the central metal ion in the following complexes: \(K_{3}[Co(C_{2}O_{4})_{3}]\)
- Q5.23(ii): Give the oxidation state, d orbital occupation and coordination number of the central metal ion in the following complexes: cis-\([CrCl_{2}(en)_{2}]Cl\)
- Q5.23(iii): Give the oxidation state, d orbital occupation and coordination number of the central metal ion in the following complexes: \((NH_{4})_{2}[CoF_{4}]\)
- Q5.23(iv): Give the oxidation state, d orbital occupation and coordination number of the central metal ion in the following complexes: \([Mn(H_{2}O)_{6}]SO_{4}\)
- Q5.24 (i): Write down the IUPAC name for the complex and indicate the oxidation state, electronic configuration and coordination number. Also give stereochemistry and magnetic moment of the complex: (K[Cr(H_{2}O)_{2}(C_{2}O_{4})_{2}].3H_{2}O)
- Q5.24 (ii): Write down the IUPAC name for the complex and indicate the oxidation state, electronic configuration and coordination number. Also give stereochemistry and magnetic moment of the complex: ([Co(NH_{3})_{5}Cl]Cl_{2})
- Q5.24 (iii): Write down the IUPAC name for the complex and indicate the oxidation state, electronic configuration and coordination number. Also give stereochemistry and magnetic moment of the complex: ([CrCl_{3}(py)_{3}])
- Q5.24 (iv): Write down the IUPAC name for the complex and indicate the oxidation state, electronic configuration and coordination number. Also give stereochemistry and magnetic moment of the complex: (Cs[FeCl_{4}])
- Q5.24 (v): Write down the IUPAC name for the complex and indicate the oxidation state, electronic configuration and coordination number. Also give stereochemistry and magnetic moment of the complex: (K_{4}[Mn(CN)_{6}])
- Q5.24(i): Write down the IUPAC name for each of the following complexes and indicate the oxidation state, electronic configuration and coordination number. Also give stereochemistry and magnetic moment of the complex: \(K[Cr(H_{2}O)_{2}(C_{2}O_{4})_{2}].3H_{2}O\)
- Q5.24(ii): Write down the IUPAC name for each of the following complexes and indicate the oxidation state, electronic configuration and coordination number. Also give stereochemistry and magnetic moment of the complex: \([Co(NH_{3})_{5}Cl]Cl_{2}\)
- Q5.24(iii): Write down the IUPAC name for each of the following complexes and indicate the oxidation state, electronic configuration and coordination number. Also give stereochemistry and magnetic moment of the complex: \([CrCl_{3}(py)_{3}]\)
- Q5.24(iv): Write down the IUPAC name for each of the following complexes and indicate the oxidation state, electronic configuration and coordination number. Also give stereochemistry and magnetic moment of the complex: \(Cs[FeCl_{4}]\)
- Q5.24(v): Write down the IUPAC name for each of the following complexes and indicate the oxidation state, electronic configuration and coordination number. Also give stereochemistry and magnetic moment of the complex: \(K_{4}[Mn(CN)_{6}]\)
- Q5.25: Explain the violet colour of the complex \([Ti(H_{2}O)_{6}]^{3+}\) on the basis of crystal field theory.
- Q5.25: Explain the violet colour of the complex ([Ti(H_{2}O)_{6}]^{3+}) on the basis of crystal field theory.
- Q5.26: What is meant by the chelate effect? Give an example.
- Q5.26: What is meant by the chelate effect? Give an example.
- Q5.27: Discuss briefly giving an example in each case the role of coordination compounds in: (i) biological systems (iii) analytical chemistry (ii) medicinal chemistry and (iv) extraction/metallurgy of metals.
- Q5.27(i): Discuss briefly giving an example in each case the role of coordination compounds in: biological systems
- Q5.27(ii): Discuss briefly giving an example in each case the role of coordination compounds in: medicinal chemistry
- Q5.27(iii): Discuss briefly giving an example in each case the role of coordination compounds in: analytical chemistry
- Q5.27(iv): Discuss briefly giving an example in each case the role of coordination compounds in: extraction/metallurgy of metals.
- Q5.28: How many ions are produced from the complex \(Co(NH_{3})_{6}Cl_{2}\) in solution?
- Q5.28: How many ions are produced from the complex (Co(NH_{3})_{6}Cl_{2}) in solution?
- Q5.29: Amongst the following ions which one has the highest magnetic moment value?
- Q5.29: Amongst the following ions which one has the highest magnetic moment value?
- Q5.3: Explain with two examples each of the following: coordination entity, ligand, coordination number, coordination polyhedron, homoleptic and heteroleptic.
- Q5.3: Explain with two examples each of the following: coordination entity, ligand, coordination number, coordination polyhedron, homoleptic and heteroleptic.
- Q5.30: Amongst the following, the most stable complex is
- Q5.31: What will be the correct order for the wavelengths of absorption in the visible region for the following: \([Ni(NO_{2})_{6}]^{4-}\), \([Ni(NH_{3})_{6}]^{2+}\), \([Ni(H_{2}O)_{6}]^{2+}\)?
- Q5.31: What will be the correct order for the wavelengths of absorption in the visible region for the following: ([Ni(NO_{2})_{6}]^{4-}), ([Ni(NH_{3})_{6}]^{2+}), ([Ni(H_{2}O)_{6}]^{2+})?
- Q5.4: What is meant by unidentate, didentate and ambidentate ligands? Give two examples for each.
- Q5.4: What is meant by unidentate, didentate and ambidentate ligands? Give two examples for each.
- Q5.5 (i): Specify the oxidation numbers of the metals: ([Co(H_{2}O)(CN)(en)_{2}]^{2+})
- Q5.5 (ii): Specify the oxidation numbers of the metals: ([CoBr_{2}(en)_{2}]^{+})
- Q5.5 (iii): Specify the oxidation numbers of the metals: ([PtCl_{4}]^{2-})
- Q5.5 (iv): Specify the oxidation numbers of the metals: (K_{3}[Fe(CN)_{6}])
- Q5.5 (v): Specify the oxidation numbers of the metals: ([Cr(NH_{3})_{3}Cl_{3}])
- Q5.5(i): Specify the oxidation numbers of the metals in the following coordination entities: \([Co(H_{2}O)(CN)(en)_{2}]^{2+}\)
- Q5.5(ii): Specify the oxidation numbers of the metals in the following coordination entities: \([CoBr_{2}(en)_{2}]^{+}\)
- Q5.5(iii): Specify the oxidation numbers of the metals in the following coordination entities: \([PtCl_{4}]^{2-}\)
- Q5.5(iv): Specify the oxidation numbers of the metals in the following coordination entities: \(K_{3}[Fe(CN)_{6}]\)
- Q5.5(v): Specify the oxidation numbers of the metals in the following coordination entities: \([Cr(NH_{3})_{3}Cl_{3}]\)
- Q5.6 (i): Using IUPAC norms write the formulas: Tetrahydroxidozincate(II)
- Q5.6 (ii): Using IUPAC norms write the formulas: Potassium tetrachloridopalladate(II)
- Q5.6 (iii): Using IUPAC norms write the formulas: Diamminedichloridoplatinum(II)
- Q5.6 (iv): Using IUPAC norms write the formulas: Potassium tetracyanidonickelate(II)
- Q5.6 (ix): Using IUPAC norms write the formulas: Tetrabromidocuprate(II)
- Q5.6 (v): Using IUPAC norms write the formulas: Pentaamminenitrito-O-cobalt(III)
- Q5.6 (vi): Using IUPAC norms write the formulas: Hexaamminecobalt(III) sulphate
- Q5.6 (vii): Using IUPAC norms write the formulas: Potassium tri(oxalato)chromate(III)
- Q5.6 (viii): Using IUPAC norms write the formulas: Hexaammineplatinum(IV)
- Q5.6 (x): Using IUPAC norms write the formulas: Pentaamminenitrito-N-cobalt(III)
- Q5.6(i): Using IUPAC norms write the formulas for the following: Tetrahydroxidozincate(II)
- Q5.6(ii): Using IUPAC norms write the formulas for the following: Potassium tetrachloridopalladate(II)
- Q5.6(iii): Using IUPAC norms write the formulas for the following: Diamminedichloridoplatinum(II)
- Q5.6(iv): Using IUPAC norms write the formulas for the following: Potassium tetracyanidonickelate(II)
- Q5.6(ix): Using IUPAC norms write the formulas for the following: Tetrabromidocuprate(II)
- Q5.6(v): Using IUPAC norms write the formulas for the following: Pentaamminenitrito-O-cobalt(III)
- Q5.6(vi): Using IUPAC norms write the formulas for the following: Hexaamminecobalt(III) sulphate
- Q5.6(vii): Using IUPAC norms write the formulas for the following: Potassium tri(oxalato)chromate(III)
- Q5.6(viii): Using IUPAC norms write the formulas for the following: Hexaammineplatinum(IV)
- Q5.6(x): Using IUPAC norms write the formulas for the following: Pentaamminenitrito-N-cobalt(III)
- Q5.7 (i): Using IUPAC norms write the systematic names: ([Co(NH_{3})_{6}]Cl_{3})
- Q5.7 (ii): Using IUPAC norms write the systematic names: ([Pt(NH_{3})_{2}Cl(NH_{2}CH_{3})]Cl)
- Q5.7 (iii): Using IUPAC norms write the systematic names: ([Ti(H_{2}O)_{6}]^{3+})
- Q5.7 (iv): Using IUPAC norms write the systematic names: ([Co(NH_{3})_{4}Cl(NO_{2})]Cl)
- Q5.7 (ix): Using IUPAC norms write the systematic names: ([Ni(CO)_{4}])
- Q5.7 (v): Using IUPAC norms write the systematic names: ([Mn(H_{2}O)_{6}]^{2+})
- Q5.7 (vi): Using IUPAC norms write the systematic names: ([NiCl_{4}]^{2-})
- Q5.7 (vii): Using IUPAC norms write the systematic names: ([Ni(NH_{3})_{6}]Cl_{2})
- Q5.7 (viii): Using IUPAC norms write the systematic names: ([Co(en)_{3}]^{3+})
- Q5.7(i): Using IUPAC norms write the systematic names of the following: \([Co(NH_{3})_{6}]Cl_{3}\)
- Q5.7(ii): Using IUPAC norms write the systematic names of the following: \([Pt(NH_{3})_{2}Cl(NH_{2}CH_{3})]Cl\)
- Q5.7(iii): Using IUPAC norms write the systematic names of the following: \([Ti(H_{2}O)_{6}]^{3+}\)
- Q5.7(iv): Using IUPAC norms write the systematic names of the following: \([Co(NH_{3})_{4}Cl(NO_{2})]Cl\)
- Q5.7(ix): Using IUPAC norms write the systematic names of the following: \([Ni(CO)_{4}]\)
- Q5.7(v): Using IUPAC norms write the systematic names of the following: \([Mn(H_{2}O)_{6}]^{2+}\)
- Q5.7(vi): Using IUPAC norms write the systematic names of the following: \([NiCl_{4}]^{2-}\)
- Q5.7(vii): Using IUPAC norms write the systematic names of the following: \([Ni(NH_{3})_{6}]Cl_{2}\)
- Q5.7(viii): Using IUPAC norms write the systematic names of the following: \([Co(en)_{3}]^{3+}\)
- Q5.8: List various types of isomerism possible for coordination compounds, giving an example of each.
- Q5.8: List various types of isomerism possible for coordination compounds, giving an example of each.
- Q5.9 (i): How many geometrical isomers are possible? ([Cr(C_{2}O_{4})_{3}]^{3-})
- Q5.9 (ii): How many geometrical isomers are possible? ([Co(NH_{3})_{3}Cl_{3}])
- Q5.9(i): How many geometrical isomers are possible in the following coordination entities? \([Cr(C_{2}O_{4})_{3}]^{3-}\)
- Q5.9(ii): How many geometrical isomers are possible in the following coordination entities? \([Co(NH_{3})_{3}Cl_{3}]\)
CBSE Solutions for Class 12 Chemistry Coordination Compounds
Chapters in CBSE - Class 12 Chemistry
Top Tutors who teach Coordination Compounds
Top Tutor
New Friends Colony, Delhi
10 yrs of
Exp
17 students
4653 hrs of classes completed
500
per hour
Online Classes
I help students in Classes 11–12 develop strong conceptual understanding, advanced problem-solving skills, and confidence for school, board, and competitive-level examinations. My classes cover: Algebra – equations, sequences & series, permutations & combinations, binomial theorem, complex numbers, etc. Trigonometry – identities, equations and applications Coordinate Geometry – straight lines, circles and conic sections Calculus – limits, continuity, differentiation, applications of derivatives, integration and related concepts Probability & Statistics Vectors & 3D Geometry Matrices & Determinants Application-based and higher-order problems Regular practice, tests, and detailed error analysis Exam-oriented preparation with focus on accuracy, speed, and time management My Teaching Approach Instead of simply teaching formulas, I focus on helping students understand why a concept works, when to apply it, and how to approach unfamiliar questions. Concept → Understand → Practise → Apply → Solve → Analyse → Improve Classes are personalised according to the student's current level, curriculum, learning gaps, and academic goals, with structured practice and continuous feedback. Suitable for: CBSE, ICSE, IB, IGCSE, GCSE, Cambridge, and other international curricula.
He explains all the concepts extremely well, and even gives practice questions if we are struggling with any topic. An extremely calm and composed teacher who answers all questions. I saw a huge improvement in my maths scores because of Ravi sir, and also gained a genuine interest in mathematics.
Top Tutor
Garia Baishnabghata Patuli Township, Kolkata
11 yrs of
Exp
4 students
1278 hrs of classes completed
400
per hour
Online Classes
I have taught class 12 students for 5 years.
Top Tutor
Nadakkave, Kozhikode
3 yrs of
Exp
7 students
831 hrs of classes completed
400
per hour
Online Classes
I provide online tutoring for class 12 CBSE students. It would be completely CBSE Board exam oriented following NCERT textbook and R.D Sharma for reference. Personalized doubt clearing sessions for any selected chapters or one-to-one/group class sessions for selected chapters or complete coverage of syllabus is provided according to the need of each student. All classes would be live interactive sessions. Please note I don't provide any entrance tuitions.
The teacher is great, and my sessions are going on really good. Individual attention is given, and all my doubts are getting cleared.
Top Tutor
Sector 13, Dwarka, Delhi
10 yrs of
Exp
1 student
165 hrs of classes completed
500
per hour
Online Classes
Tutor's home
I am an entrepreneur, giving online classes for past couple of years. I am certified in advanced Excel and completed my MBA in 2012. I always think of learning is the best done by observing, listening and practicing what was learnt.
Overall it is good experience. I have completed 12th tuitions from this teacher. Explain each concept clearly. Highly recommended.
Top Tutor
Bhopal, Bhopal
4 yrs of
Exp
1 student
75 hrs of classes completed
300
per hour
Online Classes
I am a mechanical engineer currently I am in pre final year in NIT BHOPAL. I have cracked jee on my own in first attempt and I also scored 90% in 12 with cbse board. I have been teaching my friends from class 11th itself. I can make subject really easy for you.
