Developing Metals 6: Metal Complexes

Question 1

Definition of ligand

Answer 1

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

Question 2

Give 2 key points of ligands

Answer 2

1. Neutral or negative ion molecule

2. Lone pair of electrons

Question 3

Other name for co-ordinate bond

Answer 3

Dative covalent bond

Question 4

Definition of complex

Answer 4

Metal ion with co- ordinately ( dative covalent ) bonded ligands

Question 5

Definition of coordination number

Answer 5

No. coordinate ( dative covalent ) bonds from ligands to metal ion

Question 6

Definition monodentate ( unidentate )

Answer 6

Ligands which form only 1 coordinate ( dative covalent ) bond to a metal ion

Question 7

Definition of bidentate

Answer 7

Ligands which form 2 coordinate ( dative covalent ) bonds to a metal ion

Question 8

Definition of polydentate

Answer 8

Ligands which form many ( more than 2 ) coordinate ( dative covalent ) bonds to a metal ion

Question 9

Give 6 examples ( formula & name ) of common monodenates

Look at notes on how to draw dot cross diagrams for them all

Answer 9

1. NH3 = ammine
2. H2O = aqua
3. Cl- = chloro
4. CN- = cyano
5. F- = fluoro
6. OH- hydroxo

Question 10

What shape does a complex with coordination number 2 give

give bond angle & be able to draw shape- refer to notes

Answer 10

Linear = 180°

Question 11

What shape does a complex with coordination number 4 in give

give bond angle & be able to draw shape- refer to notes

Answer 11

• square planar = 90°

OR

• tetrahedral = 109.5°

Question 12

What shape does a complex with coordination number 6 give

give bond angle & be able to draw shape- refer to notes

Answer 12

octahedral = 90°

Question 13

Give examples of the type of complexes that a linear shape occurs in

Answer 13

• Ag+ complexes

Question 14

Give examples of the type of complexes that a square planar shape occurs in

Answer 14

• Pt 2+
• Ni 2+

( ie. smaller ligands )

Question 15

Give examples of the type of complexes that tetrahedral shape occurs in

Answer 15

• Cl-

i.e larger ligands - when ligands are too big for six to fit

Question 16

Give examples of the type of complexes that an octahedral shape occurs in

Answer 16

• H2O
• NH3

( I.e most complexes with small ligands )

Question 17

Give an example of the 1 bidentate need to know ( and be able to draw its structure )

Answer 17

Ethandioate

Question 18

What’s the name given to the “shape” an ethandioate forms when donates 2 lone pair to a singular molecule ( crab shape )

Answer 18

Chelate ring ( looks like a crab )

Question 19

Give an example of a polydentate

Answer 19

Haemoglobin

Question 20

Describe the 4 steps for naming a complex

Answer 20

1. NUMBER of same type ligands - prefix = mono, tetra, hexa,
2. ligands in ALPHABETICAL order if more than one type & name them
3. NAME central TRANSITION METAL - ending in -ate & latinised name if comped -ve eg. Fe=ferrate, Zn=zincate
4. CHARGE on transition metal eg. Fe3+ = (III)

Question 21

Describe what each part reprints in the complex name:

Hexa cyano ferrate (III)

Answer 21

1. Hexa = no. of ligands = 6
2. Cyano = type of ligand = CN-
3. Ferrate = central transition metal = Fe
4. (III) = charge on ion = Fe 3+

Question 22

Definition of base

Answer 22

Lone pair donor

Question 23

Definition of acid

Answer 23

Lone pair acceptor

proton donor

Question 24

Be able to identify complexes as E / Z iosomers ( trans / cis )

Answer 24

Look at notes

Cis ( Z ) = same group attached on SAME side

Trans ( E ) = same group attached OPPOSITE / DIAGONAL to each other