Applications of Coordination Compounds, Properties, Importance, FAQs

Chemical compounds made up of an array of anions or neutral molecules linked to a central atom by coordinate covalent bonds are known as coordination compounds. Coordination compounds are also known as coordination complexes. Ligands are the molecules or ions that are bonded to the central atom (also known as complexing agents).

Coordination Compounds

Coordination compounds are a type of compound that belongs to the complex compound class. This is due to the chemistry involved with these molecules. Transition metals have the unique ability to generate coordination complexes. This is because of the high charge-to-mass ratio and the availability of d-orbitals.

Coordination chemistry developments have produced a variety of complex chemicals that we employ in a variety of sectors. Coordination chemicals are widely used in a variety of sectors. These include naming a few, mining and metallurgy, medical sciences, and so on.

Examples of coordination compounds

Coordination complexes are found in many biological substances. There are a plethora of additional coordination molecules that play critical roles in biological processes. During these physiological activities, the bodies make and consume a large number of complex chemicals. Chlorophyll is required for photosynthesis in plants. This chlorophyll is a combination of magnesium and porphyrin. Many of the enzymes that catalyze biological processes in our bodies are coordination complexes. Carboxypeptidase is one such example. It is a coordination molecule that also functions as an enzyme. It is required to catalyze the digestive process.

Properties of Coordination Compounds

  1. The existence of unpaired electrons that absorb light in their electronic transitions colors the coordination compounds created by the transition elements. Complexes containing Iron(II) might be green or pale green in color, whereas coordination compounds containing Iron(III) are brown or yellowish-brown in color.
  2. Because of the presence of unpaired electrons, the related coordination complexes have a magnetic character when the coordination center is a metal.
  3. Coordination compounds have a wide range of chemical reactivity. They can be involved in both inner-sphere and outer-sphere electron transfer reactions.
  4. Complex compounds containing certain ligands have the ability to catalyze or stoichiometrically help in the transition of molecules.

Werner’s Theory of Coordination Compounds

Werner developed a theory in 1893 to explain the structures, production, and nature of bonding in coordination molecules. Werner’s theory of coordination compounds is the name given to this hypothesis. Werner received the Nobel Prize in Chemistry in 1913 as the first inorganic chemist. He investigated a wide range of complicated chemicals derived from the interaction of cobalt chloride and ammonia. The core metals of coordination compounds have two valencies.

  1. Primary Valency: Primary valencies are those that a metal exhibits when simple salts are formed like NaCl, CuSO4, and so on. In current parlance, it denotes the metal’s oxidation number. For example, the major valencies of Co in CoCl3 are 3 and the oxidation state is +3. Ionizability exists for the primary valencies. These are written beyond the scope of cooperation. These are non-directional and do not offer complicated compounds in any shape. [Co(NH3)6]Cl3, 3 main valencies, +3 oxidation state.
  2. Secondary valency: Metals’ secondary valency is determined by either negative ions or neutral molecules, or both. In current parlance, it denotes the metal’s coordination number. Within the coordinating sphere, secondary valencies are written. These are directed in character and give the complex a definite geometry. These cannot be ionized. [Co(NH3)6] is an example. Cl3 has a coordination number of 6.

Importance of Coordination Compounds

Coordination compounds, such as the FeCl4 ion are so named because they contain ions or molecules that are linked to, or coordinated with, a transition metal, because they are Lewis acid-base complexes, they are also known as complex ions or coordination complexes. Ligands are the ions or molecules that bind to transition-metal ions to generate these complexes. The coordination number is the number of ligands attached to the transition metal ion. A coordination complex is any of a class of chemicals with chemical structures in which a central metal atom is surrounded by nonmetal atoms or groups of atoms, known as ligands, that are chemically linked to it. Coordination compounds include vitamin B12, hemoglobin, and chlorophyll, as well as dyes and pigments, and catalysts utilized in the synthesis of organic molecules.

Applications of Coordination Compounds

  1. Colors are assigned to coordination compounds. As a result, they have a widespread place in businesses that require vivid colorations. Phthalocyanine is a type of coordination complex that is widely used in the dyes and pigments industry. They use it to dye fabrics a specific color.
  2. Some cyanide compounds are used to electroplate a protective layer on surfaces. There are complexes that make use of coordination chemicals in photography.
  3. EDTA is another complicated chemical that we utilize to determine the hardness of the water. Coordination compounds can also be used as catalysts, which is one of their many applications. They are also gaining popularity in the polymer industry these days.
  4. The concept of coordination compounds is used far too frequently these days in the extraction of metals from their ores. The extraction of nickel and cobalt entails the utilization of these chemicals in a significant way. These metals are recovered via hydrometallurgical techniques that need a large number of complicated ions.
  5. As more coordination chemicals are synthesized, scientists and engineers now have a plethora of possibilities for refining and optimizing the processes that necessitate them.
  6. Hemoglobin is made up of Heme complex-ions with tetrapyrrole Porphyrin ring structures and a core Fe2+ ion. Vitamin B12 is made up of a tetrapyrrole porphyrin ring complex with a core Co+3 ion and has a coordination number of 6.
  7. Cisplatin is a chemotherapy drug that is used to treat cancer.
  8. The Ziegler-Natta catalyst, a mixture of titanium tetrachloride and triethyl aluminum, is employed in the polymerization of ethene.
  9. A complex metal catalyst is used in the hydrogenation of alkenes.
  10. Complex formation is critical in the identification and separation of most inorganic ions using qualitative methods of investigation. When copper sulfate solution is combined with aqueous ammonia, a deep blue complex that is water-soluble is generated. This reaction is used to identify the presence of cupric ions in salt.

Sample Problems(FAQs)

Question 1: Why do we use coordination compounds to separate metals in extractive metallurgy?

Answer:

These compounds are commonly used in the separation of metals during the extractive metallurgy process. This is due to the fact that these complex ions have the unique property of selective precipitation and solubility.

Question 2: What is meant by the chelate effect?

Answer:

A five or six membered ring is created when a bidentate or polydentate ligand has donor atoms that are positioned in such a way that when they coordinate with the central metal ion. This is known as the Chelate effect. As a result, the complex’s stability improves.

Question 3: Why are tetrahedral complexes high spin?

Answer:

Because of the narrow splitting energy gap, electrons are not compelled to pair, resulting in a significant number of unpaired electrons, i.e. high spin.

Question 4: Explain why nickel does not form low spin octahedral complexes.

Answer:

Even with a high field ligand, electron pairing does not occur in octahedral complexes, hence Ni does not form low spin octahedral complexes.

Question 5: What is geometric isomerism?

Answer:

Geometric isomerism refers to the isomerism that occurs in heteroleptic complexes as a result of different conceivable geometric configurations of the ligands.

Question 6: What is a coordination entity?

Answer:

The coordination entity is formed when the core metal atom is surrounded by ligands or ions and forms a complex.

Question 7: What is linkage isomerism?

Answer:

This isomerism occurs in coordination compounds containing ambidentate ligands. For example, in the thiocyanate ligand NCS, this ligand can be linked to the central metal atom via the sulphur or nitrogen side, resulting in two linkage isomers.

Er. Neeraj K.Anand is a freelance mentor and writer who specializes in Engineering & Science subjects. Neeraj Anand received a B.Tech degree in Electronics and Communication Engineering from N.I.T Warangal & M.Tech Post Graduation from IETE, New Delhi. He has over 30 years of teaching experience and serves as the Head of Department of ANAND CLASSES. He concentrated all his energy and experiences in academics and subsequently grew up as one of the best mentors in the country for students aspiring for success in competitive examinations. In parallel, he started a Technical Publication "ANAND TECHNICAL PUBLISHERS" in 2002 and Educational Newspaper "NATIONAL EDUCATION NEWS" in 2014 at Jalandhar. Now he is a Director of leading publication "ANAND TECHNICAL PUBLISHERS", "ANAND CLASSES" and "NATIONAL EDUCATION NEWS". He has published more than hundred books in the field of Physics, Mathematics, Computers and Information Technology. Besides this he has written many books to help students prepare for IIT-JEE and AIPMT entrance exams. He is an executive member of the IEEE (Institute of Electrical & Electronics Engineers. USA) and honorary member of many Indian scientific societies such as Institution of Electronics & Telecommunication Engineers, Aeronautical Society of India, Bioinformatics Institute of India, Institution of Engineers. He has got award from American Biographical Institute Board of International Research in the year 2005.

CBSE Class 12 Chemistry Syllabus Download PDF

Below is the CBSE Class 12 Syllabus along with the marking scheme and time duration of the Chemistry exam.

S.NoTitleNo. of PeriodsMarks
1Solutions107
2Electrochemistry129
3Chemical Kinetics107
4d -and f -Block Elements127
5Coordination Compounds127
6Haloalkanes and Haloarenes106
7Alcohols, Phenols and Ethers106
8Aldehydes, Ketones and Carboxylic Acids108
9Amines106
10Biomolecules127
Total70

CBSE Class 12 Chemistry Practical Syllabus along with Marking Scheme

The following is a breakdown of the marks for practical, project work, class records, and viva. The total number of marks for all parts is 15. The marks for both terms are provided in the table below.

Evaluation Scheme for ExaminationMarks
Volumetric Analysis08
Salt Analysis08
Content-Based Experiment06
Project Work and Viva04
Class record and Viva04
Total30

CBSE Class 12 Chemistry Syllabus (Chapter-wise)

Unit -1: Solutions

  • Raoult's law.
  • Colligative properties - relative lowering of vapour pressure, elevation of boiling point, depression of freezing point, osmotic pressure, determination of molecular masses using colligative properties, abnormal molecular mass.
  • Solutions, Types of solutions, expression of concentration of solutions of solids in liquids, solubility of gases in liquids, solid solutions.
  • Van't Hoff factor.

Unit -2: Electrochemistry

  • Redox reactions, EMF of a cell, standard electrode potential
  • Nernst equation and its application to chemical cells
  • Relation between Gibbs energy change and EMF of a cell
  • Kohlrausch's Law
  • Electrolysis and law of electrolysis (elementary idea)
  • Dry cell-electrolytic cells and Galvanic cells
  • Conductance in electrolytic solutions, specific and molar conductivity, variations of conductivity with concentration.
  • Lead accumulator
  • Fuel cells

Unit -3: Chemical Kinetics

  • Rate of a reaction (Average and instantaneous)
  • Rate law and specific rate constant
  • Integrated rate equations and half-life (only for zerfirst-order order reactions)
  • Concept of collision theory (elementary idea, no mathematical treatment)
  • Factors affecting rate of reaction: concentration, temperature, catalyst;
  • Order and molecularity of a reaction
  • Activation energy
  • Arrhenius equation

Unit -4: d and f Block Elements  

  • Lanthanoids- Electronic configuration, oxidation states, chemical reactivity and lanthanoid contraction and its consequences.
  • Actinoids- Electronic configuration, oxidation states and comparison with lanthanoids.
  • General introduction, electronic configuration, occurrence and characteristics of transition metals, general trends in properties of the first-row transition metals – metallic character, ionization enthalpy, oxidation states, ionic radii, color, catalytic property, magnetic properties, interstitial compounds, alloy formation, preparation and properties of K2Cr2O7 and KMnO4.

Unit -5: Coordination Compounds  

  • Coordination compounds - Introduction, ligands, coordination number, color, magnetic properties and shapes
  • The importance of coordination compounds (in qualitative analysis, extraction of metals and biological system).
  • IUPAC nomenclature of mononuclear coordination compounds.
  • Bonding
  • Werner's theory, VBT, and CFT; structure and stereoisomerism

Unit -6: Haloalkanes and Haloarenes  

  • Haloarenes: Nature of C–X bond, substitution reactions (Directive influence of halogen in monosubstituted compounds only). Uses and environmental effects of - dichloromethane, trichloro methane, tetrachloromethane, iodoform, freons, DDT.
  • Haloalkanes: Nomenclature, nature of C–X bond, physical and chemical properties, optical rotation mechanism of substitution reactions.

Unit -7: Alcohols, Phenols and Ethers   

  • Phenols: Nomenclature, methods of preparation, physical and chemical properties, acidic nature of phenol, electrophilic substitution reactions, uses of phenols.
  • Ethers: Nomenclature, methods of preparation, physical and chemical properties, uses.
  • Alcohols: Nomenclature, methods of preparation, physical and chemical properties (of primary alcohols only), identification of primary, secondary and tertiary alcohols, mechanism of dehydration, and uses with special reference to methanol and ethanol.

Unit -8: Aldehydes, Ketones and Carboxylic Acids   

  • Carboxylic Acids: Nomenclature, acidic nature, methods of preparation, physical and chemical properties; uses.
  • Aldehydes and Ketones: Nomenclature, nature of carbonyl group, methods of preparation, physical and chemical properties, mechanism of nucleophilic addition, the reactivity of alpha hydrogen in aldehydes, uses.

Unit -9: Amines    

  • Diazonium salts: Preparation, chemical reactions and importance in synthetic organic chemistry.
  • Amines: Nomenclature, classification, structure, methods of preparation, physical and chemical properties, uses, and identification of primary, secondary and tertiary amines.

Unit -10: Biomolecules     

  • Proteins -Elementary idea of - amino acids, peptide bond, polypeptides, proteins, structure of proteins - primary, secondary, tertiary structure and quaternary structures (qualitative idea only), denaturation of proteins; enzymes. Hormones - Elementary idea excluding structure.
  • Vitamins - Classification and functions.
  • Carbohydrates - Classification (aldoses and ketoses), monosaccharides (glucose and fructose), D-L configuration oligosaccharides (sucrose, lactose, maltose), polysaccharides (starch, cellulose, glycogen); Importance of carbohydrates.
  • Nucleic Acids: DNA and RNA.

The syllabus is divided into three parts: Part A, Part B, and Part C. Part A consist of Basic Concepts of Chemistry, which covers topics such as atomic structure, chemical bonding, states of matter, and thermochemistry. Part B consists of Topics in Physical Chemistry, which includes topics such as chemical kinetics, equilibrium, and electrochemistry. Part C consists of Topics in Organic Chemistry, which covers topics such as alkanes, alkenes, alkynes, and aromatic compounds.

Basic Concepts of Chemistry:

  • Atomic structure: This section covers the fundamental concepts of atomic structure, including the electronic configuration of atoms, the Bohr model of the atom, and the wave nature of matter.
  • Chemical bonding: This section covers the different types of chemical bonds, including ionic, covalent, and metallic bonds, as well as the concept of hybridization.
  • States of the matter: This section covers the three states of matter - solid, liquid, and gas - and the factors that influence their properties.
  • Thermochemistry: This section covers the principles of thermochemistry, including the laws of thermodynamics and the concept of enthalpy.

Chapters in Physical Chemistry:

  • Chemical kinetics: This section covers the study of the rate of chemical reactions and the factors that influence it, including the concentration of reactants, temperature, and the presence of catalysts.
  • Equilibrium: This section covers the principles of chemical equilibrium, including the concept of Le Chatelier's principle and the equilibrium constant.
  • Electrochemistry: This section covers the principles of electrochemistry, including the concept of half-cell reactions, galvanic cells, and electrolysis.

Chapters in Organic Chemistry:

  • Alkanes: This section covers the properties and reactions of alkanes, including their structure, isomerism, and combustion.
  • Alkenes: This section covers the properties and reactions of alkenes, including their structure, isomerism, and addition reactions.
  • Alkynes: This section covers the properties and reactions of alkynes, including their structure, isomerism, and addition reactions.
  • Aromatic compounds: This section covers the properties and reactions of aromatic compounds, including their structure, isomerism, and electrophilic substitution reactions.

In addition to the topics covered in the syllabus, the CBSE Class 12 Chemistry exam also tests students on their analytical and problem-solving skills, as well as their ability to apply the concepts learned in the classroom to real-world situations.

Students can also check out the Tips for the Class 12 Chemistry Exam. They can easily access the Class 12 study material in one place by visiting the CBSE Class 12 page at ANAND CLASSES (A School Of Competitions). Moreover, to get interactive lessons and study videos, download the ANAND CLASSES (A School Of Competitions) App.

Frequently Asked Questions on CBSE Class 12 Chemistry Syllabus

Q1

How many chapters are there in the CBSE Class 12 Chemistry as per the syllabus?

There are 10 chapters in the CBSE Class 12 Chemistry as per Syllabus. Students can learn all these chapters efficiently using the study materials provided at ANAND CLASSES (A School Of Competitions).

Q2

What is the marking scheme for CBSE Class 12 Chemistry practical exam according to the syllabus?

The marking scheme for CBSE Class 12 Chemistry practical exam, according to the syllabus, is 8 marks for volumetric analysis, 8 marks for salt analysis, 6 marks for the content-based experiment, 4 marks for the project and viva and 4 marks for class record and viva.

Q3

Which is the scoring chapter in Chemistry as per CBSE Class 12 syllabus?

The chapter Electrochemistry in Chemistry is the scoring chapter as per CBSE Class 12 syllabus.