transition metals

What is a transition metal?

D block element that can from at least one stable ion with an incomplete d sub-shell

Write out the electron configurations for the following

1. Ti

2. V

3. Cr

4. Mn

5. Fe

6. Co

7. Ni

8. Cu

1. [Ar] 3d2 4s2

2. [Ar] 3d3 4s2

3. [Ar] d5 4s1

4. [Ar] 3d5 4s2

5. [Ar] 3d6 4s2

6. [Ar] 3d7 4s2

7. [Ar] 3d8 4s2

8. [Ar] 3d10 4s1

Why are zincs and scandium’s stable ions not transition metals?

Its ion Sc3+ has an empty d sub shell, not partially filled.

Zinc only forms 1 stable ion of Zn2+ which has a full sub shell, not partially filled.

State some properties of transition metals

• variable oxidation states because 4s and 3d energy levels are close.

• Form coloured ions in solutions

• Good catalysts

State the colours of the following in soltuion

1. V 2+

2. V 3+

3. VO 2+

4. VO2 +

1. Violet

2. Green

3. Blue

4. Yellow

State the colour of the following ions in soltuion

1. Mn 2+

2. MnO4 -

1. Pale pink

2. Purple

State the colours of the following ions in soltuion

1. Fe 2+

2. Fe 3+

1. Pale green

2. Yellow

State the colour of the following ions in soltuion

1. Co 2+

2. Ni 2+

3. Cu 2+

1. Pink

2. Green

3. Blue

What is a complex ion?

Central transition metal ion is surrounded by ligands bonded by dative covalent bonds.

The ligands have at least one lone pair of electrons that they use to dative bonds.

Describe and give examples of monodentate, bidentate or polydentate ligands

Mono - one lone pair of electrons

H2O NH3 Cl-

Bi - two

Ethandioate , ethane-1,2-diamine

Poly- More than one dative bond

EDTA 4-

What are the shape of complex shapes dependent on?

The size of ligands and the coordination number (number of coordinate bonds)

Small (eg water/ammonia) can fit 6 around metal ion so octahedral shape

Chloride ligands are larger so you can fit 4 of them around. - square planar/tetrahedral

Ethanedioate is bigger so three fit around.

Draw and write complex ion for cis-platin

Write out Tollens reagent and show displayed formula

How to work out total oxidation state of a metal

Total OS - total OS of ligands

Displayed formula of haemoglobin

How does haemoglobin transport oxygen

Oxygen substitutes the water ligand in the lungs where oxygen concentration is high to from oxyhemoglobin. Oxyhemoglobin will give up oxygen to a place where it is needed and replaces with water.

What is the problem with haemoglobin and carbon monoxide?

If CO is inhaled the water ligand is replaced with a carbon monoxide ligand and its binds strongly so it is not readily replaced.

Which complexes show cis-trans isomerism

Octahedral complexes wit 4 ligands of the same type and two ligands of a different type

Square planar - 2 pairs of different ligands

If the two different ligands are adjacent each other you have cis isomer

When is the d sub shell split

When two ligands bond with the central metal ion

What is delta e and what is it dependent on?

Energy gap when electrons absorb light energy some move from the lowest energy level to higher energy level.

Dependent on

• central metal ion and its OS

• Type of ligand

• Coordination number