Complex Ions

Learning Outcomes

What are we learning?We are learning about Complex Ions and how to

name them.

Why are we learning it?To understand the different reactions that

transition elements undergo.

How are we going to learn it?Completing tutorial on naming complex ions and

then conducting an activity on naming.

What have we learnt so far?

1. Properties of Transition elements2. Electronic configuration3. Oxidation numbers & formation of coloured

compounds4. Redox Equations5. Precipitation reactions

ADVICE: Use this List to now make a revision page on these topics. Condense your notes!

What’s next?

COMPLEX IONS AND LIGAND FORMATION

What is a Complex Ion?

A property of transition metals is their ability to form complex ions

Complex ion:Central metal ion is surrounded by ligands

Ligand: Molecule / ion which donates a pair of electrons forming a coordinate bond (dative bond)

Coordinate bond: One of the bonded atoms has provided both electrons for the covalent bond

An example:

• Fe 2+ is the metal ion.• Ligands are the water molecules.• Coordination number is the number of coordinate bonds to the central metal

ion = 6.• Square brackets groups the species and the overall charge is written outside

the brackets.• Overall charge is the sum of the charges of the metal ion and the ligands (if

the ligands have a charge

Naming Complex Ions 1

Naming the Ligand

Naming Complex Ions 2

Naming the amount

of Ligand

Naming Complex Ions 3

Naming the transition metal:

For positively charged complex ionsA positively charged complex ion is called a

cationic complex. A cation is a positively charged ion.

Naming Complex Ions 3

Naming the transition metal

• For negatively charged complex ions

• A negatively charged complex ion is called an anionic complex. An anion is a negatively charged ion.

• The ending is changed to -ate.

Naming Complex Ions 4

Writing the charge:

Always in brackets on the end e.g:

Tetrachlorocuprate(II)

Going back to our example . . .

What’s the name?

And finally: How to write the formula

Tetrachlorocuprate(II)

Lets break it down:

Tetra = Chloro = Cuprate = (II) =

[CuCl4]2-

Hexaaquacopper(II)

Lets break it down:

Hexa = Aqua = Copper = (II)

[Cu(H2O)6]2+

Homework: (in addition to questions in green book)

Using what you know about the names and formulae of Complex Ions. Research shapes and types of bonding.

Poster format would be best, as it can then be used for revision.