Skip to main content
Ch.21 - Transition Elements and Coordination Chemistry
McMurry - Chemistry 8th Edition
McMurry8th EditionChemistryISBN: 9781292336145Not the one you use?Change textbook
All textbooksMcMurry 8th EditionCh.21 - Transition Elements and Coordination ChemistryProblem 21.115
Chapter 21, Problem 21.115

Which of the following complexes are diamagnetic?
(a) [Ni(H2O)6]2+
(b) [Co(CN)6]3-
(c) [HgI4]2- (tetrahedral) 
(d) [Cu(NH3)4]2+ (square planar) 

Verified step by step guidance
1
Identify the oxidation state and electron configuration of the central metal ion in each complex.
Determine the geometry of each complex and the type of ligands involved (strong field or weak field).
Apply crystal field theory to determine the electron distribution in the d-orbitals for each complex.
Check for unpaired electrons in the d-orbitals to determine if the complex is paramagnetic or diamagnetic.
Conclude which complexes are diamagnetic based on the absence of unpaired electrons.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Magnetism in Coordination Complexes

Magnetism in coordination complexes is determined by the presence of unpaired electrons. A complex is diamagnetic if all its electrons are paired, resulting in no net magnetic moment. Conversely, if there are unpaired electrons, the complex is paramagnetic. Understanding the electron configuration and the ligand field theory helps predict the magnetic properties of these complexes.
Recommended video:
Guided course
00:43
Coordination Complexes Example

Crystal Field Theory

Crystal Field Theory (CFT) explains how the arrangement of ligands around a central metal ion affects its electron distribution and energy levels. Ligands can cause the d-orbitals of the metal to split into different energy levels, influencing whether electrons are paired or unpaired. The geometry of the complex (e.g., octahedral, tetrahedral) plays a crucial role in this splitting and thus in determining the magnetic properties.
Recommended video:
Guided course
01:18
The study of ligand-metal interactions helped to form Ligand Field Theory which combines CFT with MO Theory.

Ligand Field Strength

Ligand field strength refers to the ability of a ligand to influence the energy levels of the d-orbitals in a metal complex. Strong field ligands, such as CN⁻, cause greater splitting of the d-orbitals, often leading to pairing of electrons and resulting in diamagnetism. In contrast, weak field ligands, like H₂O, may not cause sufficient splitting, allowing unpaired electrons and resulting in paramagnetism.
Recommended video:
Guided course
02:40
Strong-Field Ligands result in a large Δ and Weak-Field Ligands result in a small Δ.
Related Practice
Textbook Question

What is the name of the compound [Fe(H2O)5(SCN)]Cl2? 

(a) pentaaquathiocyanatoiron(III) chloride 

(b) pentaaquachlorothiocyanato iron(III) 

(c) pentaaquathiocyanatoiron(III) dichloride

(d) pentaaquathiocyanatoiron(II) chloride

494
views
Textbook Question

Assign a systematic name to each of the following ions.  

(a) [AuCl4]-

(b) [Fe(CN)6]4-

187
views
Textbook Question

Draw a crystal field energy-level diagram, and predict the number of unpaired electrons for each of the following: 

(a) [Mn(H2O)6]2+

103
views
1
rank
Textbook Question

Cobalt(III) trifluoroacetylacetonate, Co(tfac)3, is a sixc oordinate, octahedral metal chelate in which three planar, bidentate tfac ligands are attached to a central Co atom:

(a) Draw all possible diastereoisomers and enantiomers of Co(tfac)3.

105
views
Textbook Question

Draw the structure of all isomers of the octahedral complex [NbX2Cl4]- (X- = NCS-), and identify those that are linkage isomers.

99
views
Textbook Question

Classify the following ligands as monodentate, bidentate, tri-dentate, or tetradentate. Which can form chelate rings?

(a)  

(b) 

(c) 

(d) 

108
views