2.5(P1) Transition Metals Flashcards Preview

AQA A-Level Inorganic Chemistry > 2.5(P1) Transition Metals > Flashcards

Flashcards in 2.5(P1) Transition Metals Deck (31)
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1

What is the definition of transition metals?

One that forms at least one stable ion with a part-full d sub level of electrons

2

What are some properties of transition metals?

Hard/strong metals
Good conductors of heat electricity
Low chemical reactivity
High melting and boiling points
All are in the d block, not all d block are transition metals
When ions form they lose an electron in the s sub-level not d

3

What two elements don’t fit the pattern of electron configuration?

Chromium
Copper

4

What are the 4 main characteristics of transition metals?

Form complexes
Form coloured compounds
Have variable oxidation states
Have catalytic activity

This all results from their electronic structure

5

What is different about transition metals to normal metals?

The form co-ordinate bonds instead of a weak electrostatic force like most metals

This is due to a partially filled 3d sub-level

6

What are complexes?

A transition metal surrounded by ligands

Which are co-ordinately bonded to the (ion) in the middle

7

How do you draw a complex?

The metal (ion) in the middle
Surrounded but the ligand (eg water)
Arrows between the two to show the co-ordinate bond
All contained within square brackets
The charge of the metal ion if it has one on the outside (because water is neutral so it isn’t changed)

8

What is the co-ordinate number?

The number of co-ordinate bonds

9

Can you have a complex without a charge?

Yes

It’s just a complex
Not a complex ion

10

What is a ligand?

A ligand is a species that can donate one or more lone pairs to form a co-ordinate bond to the transition metal

11

How is the ligand water involved in complexes?

Only one of it’s two lone pairs are used in co-ordinate bonding
As one of the lone pairs faces the opposite direction

12

Why can transition metals form complexes?

They have a partially filled 3d sublevel

13

What are the names for complexes with a co-ordination number of:
6?
4 (x2)?
2?

6 = octahedral
4 = tetrahedral or square planar
2 = linear

14

What is a unidentate ligand?

Forms a single co-ordinate bond no matter how many lone pairs it has

15

What should you be careful of when working out the charge on a complex?

If the ligand also has a charge which should be taken into account with the metal (ion)

I.e chloride and cyanide

16

What is a bidentate ligand?

They have lone pairs on different atoms so can ‘bend’ round to form 2 co-ordinate bonds

17

Examples of a unidentate ligand?

H2O
Cl-
NH3
CN-

18

Give some examples of a bidentate ligand?

1,2 - diaminoethane(no charge)

Ethanedioate ion (2-)
Which comes from having 2 carboxyl groups on each end with the hydrogens removed

1,2 - dihydroxybenzene (no charge)

19

Why must you be careful with bidentate ligands?

It could be forming 6 co-ordinate bonds however this would only be from 3 ligands
As each bidentate ligand supplies 2 lone pairs

20

What bidentate is abbreviated and what to?

1,2 - diaminoethane

Is abbreviated to

(en)

21

What is a multidentate ligand?

They have more than one atom with a lone pair that they can donate

22

Give an example of a multidentate ligand?

EDTA (4-)

22 lone pairs
Only 6 lone pairs are used

A lone pair from each of the 4 outer oxygens
A lone pair from the 2 nitrogens

23

What is the chelate effect?

If you add EDTA to a solution of a transition metal salt, EDTA will replace all 6 water ligands in the aqua ion

2 reactants are replaced by 7 products therefore an increase in entropy moves the reaction to the right
Therefore polydentate ligands are favoured over monodentate ligands

24

What are bridges?

A bidentate ligand can form a bridge between 2 metal ions (almost like a polymer)

‘Linking’

25

Describe the prosthetic group haem?

Square planar
Carries oxygen

26

Describe haemoglobin?

The oxygen it carries forms a temporary co-ordinate bond

CO - carbon monoxide can join instead of O2 forming a permeant bond

27

What is Cisplatin?

Platinum with 2 chlorine ligands and 2 ammonia ligands (same ligand on the same side)

Square planar
Used to treat some types of cancer in chemotherapy

Z-platin

28

What is significant about transplatin? Why?

Transplatin or E-platin
Doesn’t work in chemotherapy

As cisplatin has a higher melting point as in more soluble due to it being polar (ligands on the same side = more EN)

29

What complexes do you draw if asked for:
Linear?
Tetrahedral?
Octehedral?

Linear: Ag(silver) with 2 ammonia ligands = 1+ complex
(Used in tollen’s reagent)

Tetrahedral: Co(cobalt) with 4 chlorine ligands attached = 2- complex

Octahedral: Fe(iron) with 6 water ligands attached = 2+ complex

30

What do you draw if they want an octahedral shape using a bidentate ligand?

Co(cobalt) with 3 ethandioate ions = 4- complex