NCERT Class 12 Books Chemistry Unit 9- Coordination Compounds

Safalta Expert Published by: Noor Fatima Updated Wed, 29 Jun 2022 01:36 PM IST

Highlights

Here is the information about NCERT Class 12 Books Chemistry Unit 9. You can give a read to this blog and get PDFs of the subject. 
 

Free Demo Classes

Register here for Free Demo Classes

Please fill the name
Please enter only 10 digit mobile number
Please select course
Please fill the email
Something went wrong!
Download App & Start Learning
NCERT Class 12 Books Chemistry Unit 9- Coordination Compounds is accessible here for download purposes. You can download the PDF for and learn from the book anytime you want. Students who are studying in Class 12 and candidates who are preparing for competitive exams can download the PDF for NCERT Class 12 Books Chemistry Unit 9- Coordination Compounds to learn from the reading material.  

Taking these course books as a reference can be really helpful to prepare for any sought exam. You can keep the digital form of the book handy and learn from it without any time constraints.

At safalta, you can access FREE E-BOOKS.

Source: safalta.com

These books are not just free of cost, but they are also packed with ample knowledge and information related to your studies.


We also provide FREE MOCK PAPERS, which can help you test your own yourself. These papers can help you prepare for your exams in a better way.

Here, you can learn the NCERT Class 12 Books Chemistry Unit 9- Coordination Compounds. Moreover, you can get the links for other chapters to download the links. 

The Chapter Goes Like This-


Objectives

After studying this Unit, you will be able to 
  • Appreciate the postulates of Werner’s theory of coordination compounds
  • Know the meaning of the terms: coordination entity, central atom/ ion, ligand, coordination number, coordination sphere, coordination polyhedron, oxidation number, homoleptic and heteroleptic
  • Learn the rules of nomenclature of coordination compounds;
  • Write the formulas and names of mononuclear coordination compounds
  • Define different types of isomerism in coordination compounds;
  • Understand the nature of bonding in coordination compounds in terms of the Valence Bond and
  • Crystal Field theories
  • Appreciate the importance and applications of coordination compounds in our day to day life
In the previous Unit we learnt that the transition metals form a large number of complex compounds in which the metal atoms are bound to a number of anions or
neutral molecules by sharing of electrons. In modern terminology such compounds are called coordination compounds. The chemistry of coordination compounds is an important and challenging area of modern inorganic chemistry. New concepts of chemical bonding and molecular structure have provided insights into the functioning of these compounds as vital components of biological systems. Chlorophyll, haemoglobin and vitamin B12 are coordination compounds of magnesium, iron and cobalt respectively. Variety of metallurgical processes, industrial catalysts and analytical reagents involve the use of coordination compounds. Coordination compounds also find many applications in electroplating, textile dyeing and medicinal chemistry.


Werner’s Theory of Coordination Compounds

Alfred Werner (1866-1919), a Swiss chemist was the first to formulate his ideas about the structures of coordination compounds. He prepared and characterised a large number of coordination compounds and studied their physical and chemical behaviour by simple experimental techniques. Werner proposed the concept of a primary valence and a secondary valence for a metal ion. Binary compounds such as CrCl3, CoCl2 or PdCl2 have primary valence of 3, 2 and 2 respectively. In a series of compounds of cobalt(III) chloride with ammonia, it was found that some of the chloride ions could be precipitated as AgCl on adding excess silver nitrate solution in cold but some remained in solution. 

1 mol CoCl3.6NH3 (Yellow) gave 3 mol AgCl
1 mol CoCl3.5NH3 (Purple) gave 2 mol AgCl
1 mol CoCl3.4NH3 (Green) gave 1 mol AgCl
1 mol CoCl3.4NH3 (Violet) gave 1 mol AgCl

These observations, together with the results of conductivity measurements in solution can be explained if (i) six groups in all, either chloride ions or ammonia molecules or both, remain bonded to the cobalt ion during the reaction and (ii) the compounds are formulated as shown in Table 9.1, where the atoms within the square brackets form a single entity which does not dissociate under the reaction conditions. Werner proposed the term secondary valence for the number of groups bound directly to the metal ion; in each of these examples the secondary valences are six. 

Note that the last two compounds in Table 9.1 have identical empirical formula, CoCl3.4NH3, but distinct properties. Such compounds are termed as isomers. Werner in 1898, propounded his theory of coordination compounds. The main postulates are:
1. In coordination compounds metals show two types of linkages (valences)-primary and secondary.

2. The primary valences are normally ionisable and are satisfied by negative ions.

3. The secondary valences are non ionisable. These are satisfied by neutral molecules or negative ions. The secondary valence is equal to the coordination number and is fixed for a metal.

4. The ions/groups bound by the secondary linkages to the metal have characteristic spatial arrangements corresponding to different coordination numbers. In modern formulations, such spatial arrangements are called coordination polyhedra. The species within the square bracket are coordination entities or complexes and the ions outside the square bracket are called counter ions. 

He further postulated that octahedral, tetrahedral and square planar geometrical shapes are more common in coordination compounds of transition metals. Thus, [Co(NH3)6]3+, [CoCl(NH3)5]2+ and [CoCl2(NH3)4]+ are octahedral entities, while [Ni(CO)4] and [PtCl4]2– are tetrahedral and square planar, respectively. 

Difference between a double salt and a complex

Both double salts as well as complexes are formed by the combination of two or more stable compounds in stoichiometric ratio. However, they differ in the fact that double salts such as carnallite, KCl.MgCl2.6H2O, Mohr’s salt, FeSO4.(NH4)2SO4.6H2O, potash alum, KAl(SO4)2.12H2O, etc. dissociate into simple ions completely when dissolved in water. However, complex ions such as [Fe(CN)6]4– of K4 [Fe(CN)6] do not dissociate into Fe2+ and CN– ions.
 
NCERT Class 12 Books Chemistry Unit 9- Coordination Compounds- PDF Download

Unit 9: Coordination Compounds

अध्याय 9: उपसहसंयोजन यौगिक Safalta provides the latest NCERT course books for all the major subjects of Class 12. A team of proficient teachers drafts these matters in a precise and thorough manner. You can download the PDFs for all the subjects in a chapter-wise format.

These Books are very effective in preparing for annual exams. Here is the PDF for NCERT Class 12 Books Chemistry Unit 9- Coordination Compounds.
 

Where can you download NCERT Class 12 Books Chemistry Unit 9 PDF?

Candidates can download NCERT Class 12 Books Chemistry Unit 9- Coordination Compounds PDF for free on our page. Links are given below.

Unit 9: Coordination Compounds

अध्याय 9: उपसहसंयोजन यौगिक

Why is NCERT Books Class 12 Chemistry the best study material?

The book can also help in clarifying doubts. Other benefits of studying from the NCERT Books Class 12 Chemistry are-
  • Students gain profound knowledge about Chemistry through the NCERT Books Class 12 Chemistry
  • The course books contain pictures that can help students in better understanding of the chapters
  • These books can help students in self-study

Why is NCERT Books Class 12 Chemistry so recommended for board exams?

Almost all the questions that appear in board exams are from NCERT Books Class 12 Science. Moreover, a team of professional teachers drafts these books, which become a reliable source of study for students.
 

Are CBSE Books for Class 12 Chemistry important from an examination perspective?

The chapters in CBSE Books for Class 12 Chemistry are vital for board exams and higher classes. Students should read the Unit given in the CBSE books for Class 12 Science. These stories and practice questions can help gain excellent marks.

To get outstanding marks, we provide mock test papers that can help gear-up your preparations for exams. Additionally, you can also download e-books to get yourself prepared even in a better way.
 

Free Demo Classes

Register here for Free Demo Classes

Trending Courses

Professional Certification Programme in Digital Marketing (Batch-5)
Professional Certification Programme in Digital Marketing (Batch-5)

Now at just ₹ 49999 ₹ 9999950% off

Master Certification Digital Marketing Program Batch-10
Master Certification Digital Marketing Program Batch-10

Now at just ₹ 64999 ₹ 12500048% off

Advanced Certification in Digital Marketing Online Programme (Batch-22)
Advanced Certification in Digital Marketing Online Programme (Batch-22)

Now at just ₹ 21999 ₹ 3599939% off

Advance Graphic Designing Course (Batch-9) : 90 Hours of Learning
Advance Graphic Designing Course (Batch-9) : 90 Hours of Learning

Now at just ₹ 16999 ₹ 3599953% off

Flipkart Hot Selling Course in 2024
Flipkart Hot Selling Course in 2024

Now at just ₹ 10000 ₹ 3000067% off

Advanced Certification in Digital Marketing Classroom Programme (Batch-3)
Advanced Certification in Digital Marketing Classroom Programme (Batch-3)

Now at just ₹ 29999 ₹ 9999970% off

Basic Digital Marketing Course (Batch-24): 50 Hours Live+ Recorded Classes!
Basic Digital Marketing Course (Batch-24): 50 Hours Live+ Recorded Classes!

Now at just ₹ 1499 ₹ 999985% off

WhatsApp Business Marketing Course
WhatsApp Business Marketing Course

Now at just ₹ 599 ₹ 159963% off

Advance Excel Course
Advance Excel Course

Now at just ₹ 2499 ₹ 800069% off