Coordination Chemistry

Question 1

A complex is a ____ ion surrounded by ____

Answer 1

metal

ligands

Question 2

____ are atoms or molecules that have lone pairs of electrons or electron density that can interact with metal centres

Answer 2

Ligands

Question 3

A complex ligand is a ____. A simple ligand is a ____.

Answer 3

molecule

atom

Question 4

Ligands act as lewis ____.

Answer 4

Bases

Question 5

Ligands have lone pairs which they can donate to a ____

Answer 5

metal center

Question 6

the central atom in a complex is a ____ _____

Answer 6

metal ion

Question 7

Metals centers act as lewis ___.

Answer 7

acids

Question 8

Lewis bases ____ lone pairs

Answer 8

donate

Question 9

Lewis acids ____ lone pairs

Answer 9

accept

Question 10

Name two things that characterize complexes

Answer 10

1. Variable oxidation states due to variable occupation of the d-shell of the metal
2. Higher covalent character in the bonds between the ligand and transition metal compared to pretransition metals

Question 11

Do metals centers and ligands form simple ionic lattices?

Answer 11

no

Question 12

What are the bonds between a metal center and ligands called? (2 possible answers)

Answer 12

Coordinate covalent bonds

dative bonds

Question 13

What is the general formula for a complex?

Answer 13

[MLn]^m+

Question 14

Define coordination number

Answer 14

the number of ligands bound to M^x+

Question 15

Ligands can be …? (anionic, neutral, cationic)

Answer 15

anionic or neutral

Question 16

Are ligands monoatomic or polyatomic?

Answer 16

Trick question, the answer is both!

Question 17

The name of ____ ligands ends in an “o”

Answer 17

anionic

Question 18

Define denticity

Answer 18

the number of atoms on the ligand that are used to bind to a metal

Question 19

What are the two ways a ligand can be polydentate (denticity >1)?

Answer 19

Chelation

bridging

Question 20

Define chelating

Answer 20

when 2 or more atoms on the same ligand bind to the

same metal ion

Question 21

Define bridging

Answer 21

when the same ligand binds to more than one metal ion

Question 22

What is the shape formed for a coordination number of 6?

Answer 22

octahedral

Question 23

What is the shape formed for a coordination number of 4?

Answer 23

square planar or tetrahedral

Question 24

What is the shape formed for a coordination number of 5?

Answer 24

trigonal bipyramidal

square pyramidal

Question 25

What is the shape formed for a coordination number of 2?

Answer 25

linear

Question 26

What is the shape formed for a coordination number of 3?

Answer 26

trigonal planar

Question 27

What are the two geometric isomers for square planar?

Answer 27

cis and trans

Question 28

For anionic complexes the metal name should end with "___"

Answer 28

-ate

Question 29

What is the difference between an coordinate covalent bond and a covalent bond?

Answer 29

In the coordinate covalent bond only the ligand is donating e- for sharing where as in a covalent bond both parties would put forth e- for sharing

Question 30

What is a coordinated complex?

Answer 30

A complex that is associated with an ion

Question 31

What symbol is used to denote bridging ligands?

Answer 31

µ (greek letter mu)

Question 32

What is meant when it is said that a molecule is paramagnetic?

Answer 32

The molecule is attracted to an external magnetic field (paramagnetism is a result of unpaired e-)

Question 33

What is meant when it is said that a molecule is diamagnetic?

Answer 33

The molecule is not attracted to (in fact it is slightly repeled) by an external magnetic field (diamagnetism is a result of all e- being spin paired)

Question 34

How many d orbitals have e- density between the axes and how many d orbitals have e- on the axes?

Answer 34

3 in between the axes | 2 on the axes

Question 35

The CF splitting energy _____(decreases/increases) as you go down periodic table

Answer 35

increases

Question 36

In general, the higher the oxidation state the _____ (lesser/greater) the CF splitting energy

Answer 36

greater

Question 37

An increase in the number of ligands and e- results in a greater e- repulsion between ligands and and metals so the CF splitting energy is ____(lower/higher)

Answer 37

higher

Question 38

Which generally has a higher CF splitting an octehedral complex or a tetrahedral complex?

Answer 38

Octehedral

Question 39

When does high spin occur?

Answer 39

At the point where there is the maximum number of unpaired e-

Question 40

When does lowspin occur?

Answer 40

When e- are all paired in lower energy orbitals before the higher energy orbitals

Question 41

In the crystal field theory ligands are treated as ____ ____

Answer 41

point charges

Question 42

In the crystal field theory there is no overlap between ___ ___ and ____ ____

Answer 42

ligand orbitals and metal orbitals

Question 43

Is low or high spin more favourable?

Answer 43

low spin is more favourable