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NEET Coordination Compounds: 5 practice MCQs with answers

By the PrepMatic team · Updated 9 Oct 2026 · 3 min read

Coordination Compounds is a compact Class 12 chapter, and almost every question in it follows a small set of rules: how to name a complex, how to count its oxidation state and coordination number, which geometry and magnetism to expect, and which isomers are possible. The five MCQs below practise exactly those.

What this chapter covers in the NEET syllabus

Coordination Compounds is an NMC unit and a Class 12 NCERT chapter. The topics are:

• Werner's theory, and the terms ligand, central atom, coordination number, coordination sphere and denticity.
• Types of ligands: unidentate, bidentate (such as ethane-1,2-diamine, written en) and ambidentate, and chelation.
• IUPAC nomenclature of mononuclear coordination compounds.
• Isomerism: structural (ionisation, linkage, coordination, hydrate) and stereoisomerism (geometrical and optical).
• Bonding: valence bond theory and the basic ideas of crystal field theory, with colour and magnetic properties.
• The importance of coordination compounds, including qualitative analysis, metal extraction and biological systems.

Five practice MCQs on Coordination Compounds

Question 1

The oxidation state of cobalt in [Co(NH₃)₆]Cl₃ is:

• A. +2
• B. +3
• C. +6
• D. 0

Question 2

The IUPAC name of K₃[Fe(CN)₆] is:

• A. potassium hexacyanidoferrate(II)
• B. tripotassium hexacyanidoferrate(III)
• C. potassium hexacyanidoferrate(III)
• D. potassium ferricyanate

Question 3

The coordination number of platinum in [Pt(en)₂Cl₂]²⁺ is (en = ethane-1,2-diamine, a bidentate ligand):

• A. 3
• B. 4
• C. 2
• D. 6

Question 4

[Ni(CN)₄]²⁻ is square planar. Its hybridisation and magnetic behaviour are:

• A. dsp², diamagnetic
• B. sp³, paramagnetic
• C. sp³, diamagnetic
• D. dsp², paramagnetic

Question 5

[Co(NH₃)₅Br]SO₄ and [Co(NH₃)₅SO₄]Br are examples of:

• A. linkage isomers
• B. coordination isomers
• C. hydrate isomers
• D. ionisation isomers

Answers and explanations

1. B. Ammonia is neutral and three Cl⁻ ions outside the bracket make the complex ion 3+. So the charge on Co is +3.
2. C. The cation is named first, without a numerical prefix: potassium. The ligand CN⁻ is cyanido, with the prefix hexa for six. Iron in an anionic complex takes the ending -ate (ferrate). The complex ion has charge 3−, K₃ supplies +3 and six CN⁻ give −6, so iron is +3, written (III).
3. D. Each en ligand binds through two nitrogen atoms, so two en molecules supply four donor atoms. Two chloride ligands add two more. The coordination number is 4 + 2 = 6, and the complex is octahedral.
4. A. Ni²⁺ is 3d⁸. The strong-field ligand CN⁻ pairs up the d electrons and frees one 3d orbital, giving dsp² hybridisation, a square planar shape and no unpaired electrons, so the complex is diamagnetic. Compare [NiCl₄]²⁻, which is tetrahedral (sp³) and paramagnetic.
5. D. The two compounds have the same formula but exchange sulphate and bromide between the coordination sphere and the counter-ion. They give different ions in solution, which defines ionisation isomerism.

How to prepare Coordination Compounds

• Learn the naming rules as steps. Ligands first in alphabetical order, then the metal. Add prefixes di, tri, tetra for simple ligands and bis, tris for complex ones. For anionic complexes the metal ends in -ate, and the oxidation state is written in Roman numerals in brackets. Practise 15 names in both directions (formula to name and name to formula).
• Memorise common ligands and their names: aqua, ammine, carbonyl, cyanido, chlorido, hydroxido, oxalato, en. Know which are strong field (CN⁻, CO) and which are weak (halides).
• Use a fixed procedure for geometry and magnetism. Find the metal's oxidation state and d-electron count, decide whether the ligand is strong or weak field, then fill electrons (or use crystal field splitting), count unpaired electrons and assign hybridisation.
• List the isomer types with a standard example of each, including geometrical isomers of [Ma₂b₂] square planar and [Ma₃b₃] octahedral, and optical isomers of [M(en)₃].
• Memorise the applications: EDTA in hardness estimation, cisplatin in cancer therapy, haemoglobin, chlorophyll and vitamin B₁₂.

Naming and isomerism are rule-based, so daily practice of five complexes makes them automatic. See the NEET Chemistry preparation guide for planning, and the NEET syllabus for the unit list.

Take a full Coordination Compounds test on PrepMatic

Naming and isomerism improve with repetition, and each PrepMatic topic test (about 15 questions in 30 minutes) is another chance to practise them with NEET's negative marking in the score. Topic tests are part of the free Basic plan. More chapters are on the practice hub.

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