JEE Mains Chemistry · Teaching notes

Coordination Compounds — JEE Mains Chemistry

Coordination Compounds has 215 past-year questions from 2021 to 2026, and 63 of them ask for a number rather than an option. Most of them run the same short routine: find the metal's oxidation state and d-electron count, decide whether the ligand is strong or weak field, and then read off what the question wants, whether that is a hybridisation, a count of unpaired electrons, a spin-only moment, a CFSE or the wavelength absorbed. The rest is precise recall, where one swapped pair costs the mark: which ions sit outside the bracket, how many isomers a formula type allows, the order of the spectrochemical series, and a handful of named complexes.

Every subtopic, worked example, formula and trap in one printable document — answers shown, ready to share.

All 215 past questions JEE Mains Chemistry strategy JEE Mains home

Subtopic notes

Formula & revision sheet

12 formulas · 11 reference tables · 53 gotchas across all subtopics — the exam-eve cheat-sheet

Werner's Theory and Ionisable Ligands

Formulas (2)

Counting the ions outside the coordination sphere · Precipitate from the ionisable ions $n_{\mathrm{AgCl}} = n_{\text{complex}} \times (\text{number of } \mathrm{Cl^-} \text{ outside } [\;]) \qquad \Delta T_f = i\,K_f\,m$
Primary valency, secondary valency and double salts · Oxidation state of the central metal $x + \sum q_{\text{ligands}} = q_{\text{complex ion}}$

Watch out for (5)

Chloride inside the bracket never precipitates
→ Counting the ions outside the coordination sphere
Use the portion that was actually tested
→ Counting the ions outside the coordination sphere
Read which ratio the question wants
→ Counting the ions outside the coordination sphere
Primary valency is the oxidation state, not the ionisable count
→ Primary valency, secondary valency and double salts
A complex counter-ion changes the metal's charge
→ Primary valency, secondary valency and double salts

Ligands, Denticity and Nomenclature

Formulas (1)

IUPAC names, oxidation state and d-electron count of complexes · Oxidation state and d count $x + \sum q_{\text{ligands}} = q_{\text{complex}} \qquad n_d = \text{group number} - x$

Reference tables (2)

Denticity and types of ligands9 rows

Ligand	Donor atom(s)	Denticity	Type
$\mathrm{NH_3}$ , $\mathrm{H_2O}$	N; O	1	Monodentate, neutral
$\mathrm{NO_2^-}$	N (nitro) or O (nitrito)	1	Ambidentate
$\mathrm{SCN^-}$	S (thiocyanato) or N (isothiocyanato)	1	Ambidentate
$\mathrm{CN^-}$	C (cyanido) or N (isocyanido)	1	Ambidentate
en, $\mathrm{H_2NCH_2CH_2NH_2}$	Two N	2	Chelating, neutral
Oxalate, $\mathrm{C_2O_4^{2-}}$	Two O	2	Chelating, not ambidentate Oxalate uses both oxygens at once; it has no choice of donor atom, so it is not ambidentate.
Biuret, $\mathrm{H_2NCONHCONH_2}$	Two carbonyl O, or two deprotonated amide N in alkali	2	Chelating
EDTA⁴⁻	Two N and four O	6	Chelating; octahedral even around Ca²⁺
$\mathrm{PPh_3}$ (in Wilkinson's catalyst)	P	1	σ-donor and π-acceptor

Chelating and ambidentate are different ideas: a chelate uses two atoms together, an ambidentate ligand uses one of two.

Nickel dimethylglyoximate and copper sulphate pentahydrate8 rows

Feature	Value	Reason
Colour of $\mathrm{[Ni(dmgH)_2]}$	Red (rosy red precipitate)	Used to detect Ni²⁺ in ammoniacal solution
Geometry and magnetism of $\mathrm{[Ni(dmgH)_2]}$	Square planar, diamagnetic	d⁸ Ni²⁺ with dsp² hybridisation; N–Ni–N angles close to 90°
H atoms in $\mathrm{[Ni(dmgH)_2]}$	14	Two ligands of $\mathrm{C_4H_7N_2O_2^-}$
H atoms in hydrogen bonds	2	One O–H···O bridge on each side; the other 12 H are in methyl groups
Five-membered rings in $\mathrm{[Ni(dmgH)_2]}$	2	One chelate ring per dmgH⁻; the other two rings are six-membered
Charge of the ligand as bound	−1 (dmgH⁻)	One oxime proton is lost; dmgH₂ itself is neutral
Waters bonded to Cu in $\mathrm{CuSO_4\cdot 5H_2O}$	4	Secondary valency 4 in the textbook formula $\mathrm{[Cu(H_2O)_4]SO_4\cdot H_2O}$
Hydrogen-bonded water in $\mathrm{CuSO_4\cdot 5H_2O}$	1	Held between sulphate and coordinated water, not bonded to Cu

Nickel dimethylglyoximate and blue vitriol are asked as facts, so the numbers in this table are worth memorising.

Watch out for (7)

A chelating ligand is not ambidentate
→ Denticity and types of ligands
Nitrogen and phosphorus ligands bond differently
→ Denticity and types of ligands
Wilkinson's catalyst carries triphenylphosphine
→ Denticity and types of ligands
dmgH⁻ is an anion when it binds
→ Nickel dimethylglyoximate and copper sulphate pentahydrate
Blue vitriol has a longer story than four waters
→ Nickel dimethylglyoximate and copper sulphate pentahydrate
Oxido, not oxo; manganate, not permanganate
→ IUPAC names, oxidation state and d-electron count of complexes
Bis and tris for ligands that already carry a number
→ IUPAC names, oxidation state and d-electron count of complexes

Isomerism in Coordination Compounds

Formulas (1)

Optical isomers and total stereoisomers of octahedral complexes · Counting stereoisomers $N_{\text{stereo}} = N_{\text{achiral geometrical}} + 2\,N_{\text{chiral geometrical}}$

Reference tables (2)

Types of structural isomerism in complexes4 rows

Type	What changes	Example pair or member	How to tell
Linkage	Donor atom of an ambidentate ligand	$\mathrm{[Co(NH_3)_5(NO_2)]Cl_2}$ and $\mathrm{[Co(NH_3)_5(ONO)]Cl_2}$	Colour and infrared spectrum differ
Ionisation	Which anion is inside the bracket	$\mathrm{[Co(NH_3)_5SO_4]Br}$ and $\mathrm{[Co(NH_3)_5Br]SO_4}$	$\mathrm{AgNO_3}$ test for the halide, $\mathrm{BaCl_2}$ test for sulphate
Coordination	Which metal holds which ligands	$\mathrm{[Co(NH_3)_6][Cr(CN)_6]}$ and $\mathrm{[Cr(NH_3)_6][Co(CN)_6]}$	Needs a complex cation AND a complex anion of different metals
Solvate (hydrate)	Water inside or outside the sphere	$\mathrm{[Cr(H_2O)_6]Cl_3}$ and $\mathrm{[Cr(H_2O)_5Cl]Cl_2\cdot H_2O}$	Number of chlorides precipitated by $\mathrm{AgNO_3}$ (3 and 2)

Ionisation and hydrate isomers are told apart by what precipitates; linkage isomers need an ambidentate ligand.

Geometrical isomers of square planar and octahedral complexes8 rows

Type	Example	Geometrical isomers	Names
Tetrahedral $\mathrm{MABCD}$	An sp³ complex MABXL	0	All corners equivalent
Square planar $\mathrm{MA_2B_2}$	$\mathrm{[Pt(NH_3)_2Cl_2]}$	2	cis and trans (cisplatin is the cis form)
Square planar $\mathrm{MABCD}$	$\mathrm{[Pt(py)(NH_3)BrCl]}$	3	Each of B, C, D trans to A in turn
Octahedral $\mathrm{MA_4B_2}$	$\mathrm{[Co(NH_3)_4Cl_2]^+}$	2	cis and trans
Octahedral $\mathrm{MA_3B_3}$	$\mathrm{[Co(NH_3)_3Cl_3]}$	2	fac and mer
Octahedral $\mathrm{M(AA)_2B_2}$	$\mathrm{[Co(en)_2Cl_2]^+}$	2	cis and trans (cis is also chiral)
Octahedral $\mathrm{M(AA)_3}$	$\mathrm{[Co(en)_3]^{3+}}$	0	Only optical isomers
Octahedral $\mathrm{MA_5B}$	$\mathrm{[Co(CN)_5(NC)]^{3-}}$	0	One odd ligand has only one kind of position

Count geometrical isomers from the formula type; the metal and the ligands' names do not matter.

Watch out for (7)

Coordination isomerism needs two different metals
→ Types of structural isomerism in complexes
Ionisation isomers give different ions, not different amounts
→ Types of structural isomerism in complexes
Tetrahedral complexes have no cis–trans isomers
→ Geometrical isomers of square planar and octahedral complexes
Do not count the cis enantiomers as geometrical isomers
→ Geometrical isomers of square planar and octahedral complexes
Changing Ni²⁺ to Pt²⁺ changes the geometry
→ Geometrical isomers of square planar and octahedral complexes
A stereoisomer count includes the optical isomers
→ Optical isomers and total stereoisomers of octahedral complexes
Look for the mirror plane, not for four different groups
→ Optical isomers and total stereoisomers of octahedral complexes

Hybridisation and Magnetism: Valence Bond Theory

Formulas (1)

Inner-orbital and outer-orbital octahedral complexes · Octahedral hybridisation in valence bond theory $\text{strong field: } d^2sp^3 = (n-1)d^2\,ns\,np^3 \;(\text{inner, low spin}) \qquad \text{weak field: } sp^3d^2 = ns\,np^3\,nd^2 \;(\text{outer, high spin})$

Reference tables (2)

Four-coordinate complexes: tetrahedral or square planar9 rows

Complex	Metal and d count	Hybridisation and shape	Unpaired electrons
$\mathrm{Ni(CO)_4}$	Ni(0), 3d¹⁰ after 4s → 3d	sp³, tetrahedral	0 (diamagnetic) Ni(CO)₄ is diamagnetic; a statement calling it paramagnetic is false.
$\mathrm{[Ni(CN)_4]^{2-}}$	Ni²⁺, d⁸	dsp², square planar	0 (diamagnetic)
$\mathrm{[NiCl_4]^{2-}}$	Ni²⁺, d⁸	sp³, tetrahedral	2 (paramagnetic)
$\mathrm{[PtCl_4]^{2-}}$ , $\mathrm{[Pt(NH_3)_2Cl_2]}$	Pt²⁺, 5d⁸	dsp², square planar	0 (diamagnetic)
$\mathrm{[Cu(NH_3)_4]^{2+}}$	Cu²⁺, d⁹	Square planar	1 (paramagnetic)
$\mathrm{[Cu(CN)_4]^{3-}}$	Cu⁺, d¹⁰	sp³, tetrahedral	0 (diamagnetic)
$\mathrm{[Zn(NH_3)_4]^{2+}}$	Zn²⁺, d¹⁰	sp³, tetrahedral	0 (diamagnetic)
$\mathrm{[CoCl_4]^{2-}}$	Co²⁺, d⁷	sp³, tetrahedral	3 (paramagnetic)
$\mathrm{[MnBr_4]^{2-}}$	Mn²⁺, d⁵	sp³, tetrahedral	5 (paramagnetic)

For a four-coordinate complex decide the shape first; the magnetism follows from it.

Hybridisation, geometry and the limits of valence bond theory6 rows

Hybridisation	Coordination number and shape	d orbital used	Example
sp	2, linear	None	$\mathrm{[Ag(NH_3)_2]^+}$ , $\mathrm{[Ag(CN)_2]^-}$
sp³	4, tetrahedral	None	$\mathrm{[MnBr_4]^{2-}}$ , $\mathrm{Ni(CO)_4}$
dsp²	4, square planar	Inner $3d_{x^2-y^2}$	$\mathrm{[Ni(CN)_4]^{2-}}$
dsp³	5, trigonal bipyramidal	Inner $3d_{z^2}$	$\mathrm{Fe(CO)_5}$
d²sp³	6, octahedral (inner orbital)	Inner $3d_{x^2-y^2}$ and $3d_{z^2}$	$\mathrm{[Co(NH_3)_6]^{3+}}$ , $\mathrm{[Co(C_2O_4)_3]^{3-}}$
sp³d²	6, octahedral (outer orbital)	Outer $4d_{x^2-y^2}$ and $4d_{z^2}$	$\mathrm{[CoF_6]^{3-}}$ , $\mathrm{[FeF_6]^{3-}}$

The d orbitals used are the ones that point at the ligands.

Watch out for (7)

Spin paired is low spin; spin free is high spin
→ Inner-orbital and outer-orbital octahedral complexes
Octahedral nickel(II) is always outer orbital
→ Inner-orbital and outer-orbital octahedral complexes
Two textbook shortcuts that JEE keys have used
→ Inner-orbital and outer-orbital octahedral complexes
Ni(CO)₄ and [NiCl₄]²⁻ are both tetrahedral but differ in d count
→ Four-coordinate complexes: tetrahedral or square planar
[Ni(CN)₄]²⁻ is dsp², not sp³
→ Four-coordinate complexes: tetrahedral or square planar
sp³ can be diamagnetic or paramagnetic
→ Hybridisation, geometry and the limits of valence bond theory
Anionic ligands are not the strongest
→ Hybridisation, geometry and the limits of valence bond theory

Crystal Field Splitting, the Spectrochemical Series and Colour

Formulas (2)

Octahedral and tetrahedral splitting of the d orbitals · Crystal field splitting $E(e_g) = +0.6\Delta_o,\; E(t_{2g}) = -0.4\Delta_o \qquad E(t_2) = +0.4\Delta_t,\; E(e) = -0.6\Delta_t \qquad \Delta_t = \tfrac{4}{9}\Delta_o$
Colour, absorbed wavelength and the splitting energy · Energy of the light absorbed $\Delta = \frac{hc}{\lambda} \qquad \Delta_{\text{molar}} = \frac{N_A\,hc}{\lambda}$

Reference tables (1)

Spectrochemical series and the size of the splitting8 rows

Ligand	Donor atom	Place in the series	Field
$\mathrm{I^-}$ , $\mathrm{Br^-}$	I, Br	Weakest	Weak
$\mathrm{SCN^-}$	S	Between Br⁻ and Cl⁻	Weak
$\mathrm{Cl^-}$ , $\mathrm{S^{2-}}$ , $\mathrm{F^-}$	Cl, S, F	Below OH⁻	Weak
$\mathrm{OH^-}$ , $\mathrm{C_2O_4^{2-}}$	O	Just below water	Weak
$\mathrm{H_2O}$	O	Middle of the series	Weak for most M²⁺; strong enough to pair Co³⁺
$\mathrm{NCS^-}$ , $\mathrm{EDTA^{4-}}$	N; N and O	Just above water	Intermediate
$\mathrm{NH_3}$ , en	N	Above EDTA⁴⁻; en above NH₃	Strong for M³⁺
$\mathrm{CN^-}$ , CO	C	Strongest	Strong CO is neutral yet the strongest ligand: its π back-bonding, not its charge, widens the gap.

Weak to strong: I⁻ < Br⁻ < SCN⁻ < Cl⁻ < S²⁻ < F⁻ < OH⁻ < C₂O₄²⁻ < H₂O < NCS⁻ < EDTA⁴⁻ < NH₃ < en < CN⁻ < CO.

Watch out for (7)

The tetrahedral pattern is upside down
→ Octahedral and tetrahedral splitting of the d orbitals
Convert Δt to Δo with 9/4
→ Octahedral and tetrahedral splitting of the d orbitals
S-bonded thiocyanate is weak, N-bonded is not
→ Spectrochemical series and the size of the splitting
Splitting energy and CFSE are different quantities
→ Spectrochemical series and the size of the splitting
A stronger field absorbs a SHORTER wavelength
→ Colour, absorbed wavelength and the splitting energy
Absorbed colour is not the colour seen
→ Colour, absorbed wavelength and the splitting energy
Energy absorbed is not intensity
→ Colour, absorbed wavelength and the splitting energy

High and Low Spin Configurations and CFSE

Formulas (2)

High-spin and low-spin octahedral configurations · Spin state criterion $\Delta_o > P \Rightarrow \text{low spin } (t_{2g} \text{ filled first}) \qquad \Delta_o < P \Rightarrow \text{high spin}$
Crystal field stabilisation energy of octahedral complexes · Octahedral CFSE $\text{CFSE} = \left(-0.4\,n_{t_{2g}} + 0.6\,n_{e_g}\right)\Delta_o$

Reference tables (1)

Tetrahedral configurations and their CFSE10 rows

d count	Configuration	Unpaired electrons	CFSE
d⁰	$e^0t_2^0$	0	0
d¹	$e^1t_2^0$	1	$-0.6\Delta_t$
d²	$e^2t_2^0$	2	$-1.2\Delta_t$
d³	$e^2t_2^1$	3	$-0.8\Delta_t$
d⁴	$e^2t_2^2$	4	$-0.4\Delta_t$
d⁵	$e^2t_2^3$	5	0
d⁶	$e^3t_2^3$	4	$-0.6\Delta_t$
d⁷	$e^4t_2^3$	3	$-1.2\Delta_t$
d⁸	$e^4t_2^4$	2	$-0.8\Delta_t$
d¹⁰	$e^4t_2^6$	0	0

Tetrahedral complexes are always high spin, so each d count has exactly one row.

Watch out for (7)

t₂g³eg¹ is the weak-field configuration
→ High-spin and low-spin octahedral configurations
Pairs and unpaired electrons are different counts
→ High-spin and low-spin octahedral configurations
In a tetrahedron, e is filled first
→ Tetrahedral configurations and their CFSE
A tetrahedral CFSE is measured in Δt
→ Tetrahedral configurations and their CFSE
CFSE is not the splitting energy
→ Crystal field stabilisation energy of octahedral complexes
Zero CFSE means high-spin d⁵ or d¹⁰
→ Crystal field stabilisation energy of octahedral complexes
Rules of thumb can clash with the numbers
→ Crystal field stabilisation energy of octahedral complexes

Spin-Only Magnetic Moment

Formulas (2)

Spin-only magnetic moment from unpaired electrons · Spin-only magnetic moment $\mu_{\text{spin-only}} = \sqrt{n(n+2)}\ \text{BM}$
Counting paramagnetic species in a list · Paramagnetic test $n \geq 1 \Rightarrow \text{paramagnetic} \qquad n = 0 \Rightarrow \text{diamagnetic}$

Reference tables (1)

Unpaired electrons and moments of high-spin aqua ions10 rows

Aqua ion (high spin)	d count	Unpaired electrons	Spin-only moment (BM)
$\mathrm{Ti^{3+}}$	d¹	1	1.73
$\mathrm{V^{3+}}$	d²	2	2.83
$\mathrm{V^{2+}}$ , $\mathrm{Cr^{3+}}$	d³	3	3.87
$\mathrm{Cr^{2+}}$ , $\mathrm{Mn^{3+}}$	d⁴	4	4.90
$\mathrm{Mn^{2+}}$ , $\mathrm{Fe^{3+}}$	d⁵	5	5.92 The maximum: a d⁵ ion with a weak-field ligand.
$\mathrm{Fe^{2+}}$ , $\mathrm{Co^{3+}}$ (with F⁻)	d⁶	4	4.90
$\mathrm{Co^{2+}}$	d⁷	3	3.87
$\mathrm{Ni^{2+}}$	d⁸	2	2.83
$\mathrm{Cu^{2+}}$	d⁹	1	1.73
$\mathrm{Zn^{2+}}$	d¹⁰	0	0

Cr³⁺ is 3.87 BM with every ligand, because d³ has only one octahedral configuration.

Watch out for (7)

Copper(I) is diamagnetic
→ Spin-only magnetic moment from unpaired electrons
Watch the units the answer is asked in
→ Spin-only magnetic moment from unpaired electrons
The same oxidation state does not explain different moments
→ Spin-only magnetic moment from unpaired electrons
Fe²⁺ and Fe³⁺ aqua ions differ by one unpaired electron
→ Unpaired electrons and moments of high-spin aqua ions
Change of ligand can reverse an order
→ Unpaired electrons and moments of high-spin aqua ions
Low-spin d⁶ is diamagnetic
→ Counting paramagnetic species in a list
Ferricyanide has one unpaired electron
→ Counting paramagnetic species in a list

Metal Carbonyls, Stability and Applications

Formulas (1)

Stability constants and the chelate effect · Overall stability constant $\beta_n = \frac{[\mathrm{ML}_n]}{[\mathrm{M}][\mathrm{L}]^n} = K_1K_2\cdots K_n \qquad K_{\text{diss}} = \frac{1}{\beta_n}$

Reference tables (2)

Synergic bonding and structures of metal carbonyls5 rows

Carbonyl	Shape at each metal	Bridging CO	Metal–metal bonds
$\mathrm{Ni(CO)_4}$	Tetrahedral	0	0
$\mathrm{Fe(CO)_5}$	Trigonal bipyramidal	0	0
$\mathrm{Cr(CO)_6}$ , $\mathrm{W(CO)_6}$	Octahedral	0	0
$\mathrm{Mn_2(CO)_{10}}$	Octahedral (five CO and one Mn–Mn bond)	0	1 Mn–Mn Decacarbonyldimanganese(0) has ten terminal CO groups and no bridge.
$\mathrm{Co_2(CO)_8}$	Two Co(CO)₃ units joined by two CO bridges	2 (with 6 terminal)	1 Co–Co

Only the dicobalt carbonyl here has bridging CO groups.

Complexes in biology, medicine, industry and analysis11 rows

Substance	Metal	Role
Chlorophyll	Mg	Photosynthetic pigment
Haemoglobin	Fe	Oxygen carrier in blood
Vitamin B₁₂ (cyanocobalamin)	Co	Anti-pernicious-anaemia factor
Cisplatin	Pt	Anticancer drug
Wilkinson's catalyst	Rh	Hydrogenation of alkenes
Ziegler–Natta catalyst	Ti (with Al)	Polymerisation of alkenes
Grubbs catalyst	Ru	Alkene metathesis
$\mathrm{[Ag(S_2O_3)_2]^{3-}}$ (from hypo)	Ag	Fixing in black-and-white photography Photography uses the thiosulphate complex, not $\mathrm{[Ag(CN)_2]^-}$ .
$\mathrm{[Ag(CN)_2]^-}$ , $\mathrm{[Au(CN)_2]^-}$	Ag, Au	Extraction by cyanide leaching; electroplating
EDTA	Ca, Mg (and Pb)	Water-hardness titration; treatment of lead poisoning
D-Penicillamine	Cu	Chelating drug for excess copper

Most match lists pair a biological or catalytic name with its metal.

Watch out for (6)

Synergic bonding strengthens the metal–carbon bond
→ Synergic bonding and structures of metal carbonyls
π-acceptors, not π-donors, stabilise low oxidation states
→ Synergic bonding and structures of metal carbonyls
Use the FREE ligand, not the total added
→ Stability constants and the chelate effect
Chelation raises stability at the same metal and charge
→ Stability constants and the chelate effect
Chlorophyll is magnesium, vitamin B₁₂ is cobalt
→ Complexes in biology, medicine, industry and analysis
EDTA is not an anticancer drug
→ Complexes in biology, medicine, industry and analysis

PYQ weightage by concept

23 concepts · 215 PYQs — where the marks actually sit, so you know what to drill first

Werner's Theory and Ionisable Ligands19 PYQs · 9%

Concept	PYQs	Share
Counting the ions outside the coordination sphere	14	7%
Primary valency, secondary valency and double salts	5	2%

Ligands, Denticity and Nomenclature23 PYQs · 11%

Concept	PYQs	Share
Denticity and types of ligands	10	5%
Nickel dimethylglyoximate and copper sulphate pentahydrate	7	3%
IUPAC names, oxidation state and d-electron count of complexes	6	3%

Isomerism in Coordination Compounds23 PYQs · 11%

Concept	PYQs	Share
Geometrical isomers of square planar and octahedral complexes	10	5%
Optical isomers and total stereoisomers of octahedral complexes	9	4%
Types of structural isomerism in complexes	4	2%

Hybridisation and Magnetism: Valence Bond Theory32 PYQs · 15%

Concept	PYQs	Share
Inner-orbital and outer-orbital octahedral complexes	13	6%
Four-coordinate complexes: tetrahedral or square planar	13	6%
Hybridisation, geometry and the limits of valence bond theory	6	3%

Crystal Field Splitting, the Spectrochemical Series and Colour28 PYQs · 13%

Concept	PYQs	Share
Colour, absorbed wavelength and the splitting energy	15	7%
Spectrochemical series and the size of the splitting	8	4%
Octahedral and tetrahedral splitting of the d orbitals	5	2%

High and Low Spin Configurations and CFSE34 PYQs · 16%

Concept	PYQs	Share
High-spin and low-spin octahedral configurations	15	7%
Crystal field stabilisation energy of octahedral complexes	14	7%
Tetrahedral configurations and their CFSE	5	2%

Spin-Only Magnetic Moment35 PYQs · 16%

Concept	PYQs	Share
Spin-only magnetic moment from unpaired electrons	19	9%
Unpaired electrons and moments of high-spin aqua ions	11	5%
Counting paramagnetic species in a list	5	2%

Metal Carbonyls, Stability and Applications21 PYQs · 10%

Concept	PYQs	Share
Synergic bonding and structures of metal carbonyls	9	4%
Stability constants and the chelate effect	6	3%
Complexes in biology, medicine, industry and analysis	6	3%

Test yourself on Coordination Compounds

20 past JEE Mains questions from this chapter, timed at 48 minutes and marked the way the exam marks it. You see your score and every answer the moment you finish. Free to start.

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Werner's Theory and Ionisable Ligands

Ligands, Denticity and Nomenclature

Isomerism in Coordination Compounds

Hybridisation and Magnetism: Valence Bond Theory

Crystal Field Splitting, the Spectrochemical Series and Colour

High and Low Spin Configurations and CFSE

Spin-Only Magnetic Moment

Metal Carbonyls, Stability and Applications

Formula & revision sheet

PYQ weightage by concept

Test yourself on Coordination Compounds

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