Transition Metals Flashcards Preview

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Flashcards in Transition Metals Deck (43):
1

Name three bidentate ligands

Ethane-1,2-diamine,
Benzene-1,2-diol
Ethanedioate ion

2

Name a hexadentate (multidentate) ligand

EDTA^4-

3

What shape do tetrachloro ligands make and why?

Tetrahedral because the ions are large so fewer can fit around the central metal ion

4

What shape is an Ag+ complex?

Linear

5

What shape is a Pt2+ complex?

Square planar

6

Why are transition metal complexes coloured?

Electrons can move between d-orbitals, and in a compound the neighbouring atoms make the orbitals have slightly different energies. Electrons absorb energy in the visible region of the spectrum to move between orbitals, so we see a combination of the colours that are not absorbed.

7

How can colorimetry be used to find the formula of a transition metal complex?

Metal ions and ligands are mixed in different ratios and the ratio that is the same as in the complex will produce the most of the complex so will absorb most light.

8

What is a transition metal?

An element that forms at least one stable ion with a part full d-shell of electrons

9

Co(II) and H2O

Pink solution

10

Cu(II) and H2O

Blue solution

11

Fe(II) and H2O

Green solution

12

Cr(III) and H2O

Ruby solution

13

Fe(III) and H2O

Violet solution - appears brown due to hydrolysis

14

V(III) and H2O

Blue solution

15

Al(III) and H2O

Colourless solution

16

Co(II) and NH3

Straw coloured solution

17

Cu(II) and NH3

Deep blue solution

18

Co(III) and NH3

Dark brown solution

19

Cr(III) and NH3

Purple solution

20

Co(II) and OH-

Blue precipitate

21

Cu(II) and OH-

Blue precipitate

22

Fe(II) and OH-

Green precipitate - turns brown due to oxidation

23

Cr(III) and OH-

Light green precipitate [Cr(H2O)3(OH)3]

Green solution [Cr(OH)6]3-

24

Fe(III) and OH-

Brown precipitate

25

Al(III) and OH-

White precipitate [Al(H2O)3(OH)3]

Colourless solution [Al(OH)4]-

26

Co(II) and Cl-

Blue solution

27

Cu(II) and Cl-

Yellow-green solution

28

Co(II) and carbonate ion

Pink precipitate

29

Cu(II) and carbonate ion

Green-blue precipitate

30

Fe(II) and carbonate ion

Green precipitate

31

Define heterogeneous catalyst

A catalyst present in a different phase than the reactants (usually a solid while the reactants are gases or liquids)

32

Define homogeneous catalyst

A catalyst in the same phase as the reactants (where an intermediate species is formed during the reaction)

33

Define a Lewis acid

An electron pair acceptor

34

Define a Lewis base

An electron pair donor

35

Why is hexaaquairon(III) acidic whereas hexaaquairon(II) isn't so much?

The Fe3+ ion is smaller and more highly charged that the Fe2+ ion so it attracts the electrons on the oxygen atoms which weakens the OH bonds in the water molecules which causes H+ ions to be released, making the solution acidic.

36

How can you distinguish between iron ions?

Add a dilute alkali, which precipitates the hydroxides with obviously different colours

37

Define amphoteric

Showing both acidic and basic properties

38

MnO4^-

Purple, +7

39

Cr2O7^2-

Orange, +6

40

VO2^+

Yellow, +5

41

VO^2+

Blue, +4

42

V^3+

Green, +3

43

Cr^3+

Green/Violet +3