Transition metals + Aqueous ions

Fe (II) in aqueous solution

[Fe(H2O)6]2+, green solution

Cu in aqueous solution

[Cu(H2O)6]2+, blue solution

Fe (III) in aqueous solution

[Fe(H2O)6]3+, pale violet bur appears orange due to some hydrolysis to (H2O)5(OH)

Al in aqueous solution

[Al(H2O)6]3+, colourless solution

Fe (II) and NaOH or NH3 dropwise

Fe(H2O)4(OH)2, green precipitate

Fe (II) and excess NaOH (aq)

No further reaction (remains green)

Cu and NaOH or NH3 dropwise

Cu(H2O)4(OH)2, blue precipitate

Cu and excess NaOH

No further reaction (remains blue)

Fe (III) and NaOH or NH3 dropwise

Fe(H2O)3(OH)3, brown precipitate

Fe (III) and excess NaOH

No further reaction (remains brown)

Al and NaOH or NH3 dropwise

Al(H2O)3(OH)3, white precipitate

Al and excess NaOH

[Al(H2O)2(OH)4]-, re-dissolves to give colourless solution

Fe (II) and excess NH3

No further reaction (remains green)

Cu and excess NH3

[Cu(H2O)2(NH3)4]2+, deep blue solution

Fe (III) and excess NH3

No further reaction (remains brown)

Al and excess NH3

No further reaction (remains white)

Fe (II) and Na2CO3

FeCO3, green precipitate

Cu and Na2CO3

CuCO3, blue-green precipitate

Fe (III) and Na2CO3

Fe(H2O)3(OH)3, brown precipitate, bubbles of CO2 gas

Al and Na2CO3

Al(H2O)3(OH)3, white precipitate, bubbles of CO2

Fe (II) and conc. HCl

[FeCl4]- yellow solution

Cu and conc. HCl

[CuCl4]2- green solution

Fe (III) and conc. HCl

[FeCl4]- yellow solution

Al and conc. HCl

[AlCl4]- colourless solution

Give the conditions for reducing vanadium

Acidic (HCl/H2SO4), Zinc as reducing agent

V +5 species and colour

VO2 +, yellow

V +4 species and colour

VO2+, blue

V +3 species and colour

V3+, green

V +2 species in acidic solution and colour

V2+, violet

Cobalt (II) and excess NH3

[Co(NH3)6]3+ (s)

Co and Na2CO3

CoCO3

Co and HCl

[CoCl4]2-

Give two equations that show how Vanadium (V) oxide acts as a heterogenous catalyst in the contact process

SO2 + V2O5 —> SO3 + V2O4

V2O4 + ½ O2 —> V2O5

give the electronic configuration of Cr

[Ar] 4s1 3d5

Give the electronic configuration of Cu

[Ar] 4s1 3s10

Define transition metal

An element that has an incomplete d sub shell in either its atoms or one of its common (stable) ions

Define ligand

A particle with a lone pair of electrons that bonds to metals by a co-ordinate bond

Define complex ion

Metal ion with co-ordinately bonded ligands

Define co-ordination number

The number of co-ordinate bonds from ligands to metal ion

Define a Lewis base

Lone pair donor

Define a Lewis acid

Lone pair acceptor

When would a linear complex occur?

In Ag+ complexes, Co-ordination number of 2

When would a square planar complex occur?

Pt2+ and Ni2+ complexes, Co-ordination number of 4

When would a tetrahedral complex occur?

With larger ligands eg, Cl- that are too big for 6 to fit, Co-ordination number of 4

When would an octahedral complex occur?

Most complexes with small ligands eg, H2O, NH3, co-ordination number of 6

Define a unidentate ligand

Ligands which form one Co-ordinate bond to a metal ion

Give examples of a unidentate ligand

Cl-, OH-, CN-, H2O, NH3

Define a bidentate ligand

Ligands which form two coordinate bonds to a metal ion

Give examples of bidentate ligands

1,2-diamimoethane, ethanedioate ion (C2O4 2-)

Define a multidentate ligand

Ligands which form more than two coordinate bonds to a metal ion

Give an example of a multidentate ligand

EDTA 4- (forms 6 bonds)