transition metals 1.3

Question 1

d block transition metals

Answer 1

metals with an incomplete d subshell in at least one of their ions

Question 2

oxidation state

Answer 2

describes the no of electrons involved in bonding, transition metals can have a different oxidation states when it forms compounds, different oxidation states have different colours

Question 3

oxidation numbers

Answer 3

1 uncombined elements = 0
2 single atoms = ion charge
3 oxygen usually -2
4 hydrogen usually +1
5 the sum of all the oxidation numbers in a neutral = 0
6 the sum of all the oxidation numbers in a polyatomic ion = charge on the ion

Question 4

oxidation =

Answer 4

increase in ox number

Question 5

reduction =

Answer 5

decrease in ox number

Question 6

a high ox number usually =

Answer 6

oxidising agent

Question 7

a low ox number usually =

Answer 7

reducing agent

Question 8

ligands

Answer 8

they’re negative ions or molecules with a non bonding pair of electrons, they can donate both of these to another atom, this is a special type of covalent bond called a dative bond

Question 9

how are ligands classified

Answer 9

based on how many electron pairs they donate (and therefore how many dative bonds they form)

Question 10

monodente

Answer 10

1 pair

Question 11

bidentate

Answer 11

2 pairs (oxalato)

Question 12

hexadente

Answer 12

6 pairs (EDTA)

Question 13

transition metal complex

Answer 13

when a ligand forms a dative bond with a central transition metal atom or ion

Question 14

coordination number

Answer 14

the number of bonds from a ligands to the central atom and helps determine the shape

Question 15

aqua

Answer 15

OH2

charge 0

Question 16

ammine

Answer 16

NH3

charge 0

Question 17

cyanido

Answer 17

CN-

charge -1

Question 18

chlorido

Answer 18

Cl-

charge -1

Question 19

fluorido

Answer 19

F-

charge -1

Question 20

bromido

Answer 20

Br-

charge -1

Question 21

iodido

Answer 21

I-

charge -1

Question 22

hydroxido

Answer 22

OH-

charge -1

Question 23

oxalato

Answer 23

O2C2O2 / C2O4 2-

charge -2

Question 24

complex formulae

Answer 24

1 the symbol of the metal is written first, then ligands in alphabetical order based on the letter/symbol that binds to the TM
2 the formula of the complex ion is enclosed within square brackets with the charge outside the square bracket with the charge outside the square brackets eg [FeCl2(OH2)4]+

Question 25

complex names

Answer 25

1 ligands are named in alphabetical order followed by the metal (and it’s oxidation state in roman numerals) 2 if there is more than one ligand it is preceded by di, tri, tetra etc 3 if the complex is a negative ion overall, the metal ends in ate 4 if the complex is a salt, the name of the positive ion proceeds the name of the negative ion

Question 26

iron as a negative ion

Answer 26

ferrate

Question 27

copper as a negative ion

Answer 27

cuprate

Question 28

when are d orbitals degenerate

Answer 28

whey there are no ligands attached to a transition metal ion

Question 29

when do d orbitals split

Answer 29

when ligands attach and this is due to the electrostatic repulsion of the approaching ligand

Question 30

strong field ligand =

Answer 30

large split = large energy difference

Question 31

weak field ligand =

Answer 31

small split = small energy difference

Question 32

how to get a spectrochemical series

Answer 32

placing ligands in order of splitting ability

Question 33

ligands in order of increasing splitting ability

Answer 33

Cl- < OH- < H2O < NH3 < CN- < CO

Question 34

the two types of catalysts

Answer 34

heterogeneous and homogeneous

Question 35

heterogeneous catalysts

Answer 35

-reactant molecules absorb into the metal surface -unpaired d electrons or infilled orbitals allow an activated complex to form by weakening the bonds within the reactant -this provides a reaction pathway with a lower energy

Question 36

homogeneous catalysts

Answer 36

-can allow intermediate complexes to form due to the ability to have different oxidation states -this gives a lower energy pathway for the reaction