2.Transition Metals

Question 1

why do you lose 4s electrons first when ionising?

Answer 1

as the orbitals get attracted by the +ve neuclues different amount,

3d gets pulled more, so 4s is in the higher energy state.

Question 2

what is a transition element?

Answer 2

has at least one stable ion with a partially filled d subshell

Question 3

what are co-ordinate bonds?

Answer 3

dative covelant bons in a transition metal.

Lone pair from one atom is shared witht he trasition metal to form a bond

Question 4

what is a ligand?

Answer 4

a molecule or ion that can donate a pair of electrons with the transition metal ion to form a coordinate bond.

Question 5

what is a complex ion?

Answer 5

a transition metal ion bonded to one or more ligands by coordinate bonds

Question 6

reaction between Hexaaqua iron(II) ion and OH^-

and why it happens.

Answer 6

[Fe(H₂O)₆]²⁺_(aq) +2OH^-_(aq) –> Fe(OH)_2(s) + 6H₂O_(l)

As OH^- has a strong attraction then water

Question 7

What happens with NH₃ ligand substitution?

Answer 7

first OH^- will displace

then when NH₃ conc is high enough it will displace as its lone pair is more avalable

Question 8

what is a monodentate ligand?

Answer 8

has one point of attachment with the transition metal ion.

Question 9

what is a bidentate ligand?

Answer 9

has two points of attraction with the ligand

Question 10

types of isomerism in complex ions?

Answer 10

cis/trans

optical isomers

Question 11

K_c =

Answer 11

the constant for ligand substitution ractions starting from water ligands

[products]/[reactants]

Question 12

K_stab = STability constant =

Answer 12

the equilibrium constant for an equilibrium existing between a transition metal ion surrounded by water ligands and the complex ion formed when the same ion has undergone a ligand substitution reaction

[Final complex ion]/[Original ion][new ligand]ⁿ

Question 13

what does stability constant tell you?

Answer 13

how stable the new ligand is in comparisson the the water ligand.

the larger the value the further to the right the equilibrim is and the more stable the complex is.

Question 14

electron config for Cr

Answer 14

…….. 3d⁵ 4s¹

as the replusion in the s orbital means that its of ahigher energy level

Question 15

electron config for Cu

Answer 15

……… 3d¹⁰ 4s¹

Question 16

4 properties of transition metals

Answer 16

1. many oxidation states
2. makes good catalysts
3. multi coloured ions
4. complex ions

Question 17

why do transition metals make good catalyst?

Answer 17

they hae variable oxidation states

easy to form intermediates

easily adsorb reactants

Question 18

why are there ions coloured?

Answer 18

they can adsorb energy from light to promote d electrons

(d shell must be partially filled)

Question 19

colour of Co²⁺ in solution

Answer 19

pink

Question 20

colour of Cu²⁺ in solution

Answer 20

blue

Question 21

colour of Fe³⁺​ in solution

Answer 21

pale green

Question 22

colour of Fe²⁺​ in solution

Answer 22

yellow

Question 23

why do transition metal ios form complex ions?

Answer 23

small, high charge density

strongly polarising, and attractive to lone pairs

Question 24

what is coordination number?

Answer 24

the numbe of coordinate bonds formed between the metal ion and its ligands.

Question 25

why do some ligands substitute with les sof them?

Answer 25

if they have a charge at somepoint the ion will no longer be attractive enough to get another ligand of the same charge

and they might be bigger ligands so dont fit

Question 26

why are two colour changes seen in some ligand substitutions?

Answer 26

as both colours are present so they mix

Question 27

name for the water, ammonia, chlride ion and CN^- ion ligands?

Answer 27

• water : aqua
• NH₃ : ammine
• Cl^- : chloro
• CN^- : cyano

Question 28

[Cu(H₂O)₆]²⁺ colour

Answer 28

Blue

Question 29

[CuCl₄]^2- colour

Answer 29

Yellow

Question 30

[Cu(NH₃)₄(H₂O)₂]²⁺colour

Answer 30

Dark blue

Question 31

[Fe(H₂O)₆]²⁺ colour

Answer 31

pale green

Question 32

[Fe(H₂O)₆]³⁺ colour

Answer 32

yellow

Question 33

[Fe(H₂O)₅SCN]²⁺ colour

Answer 33

blood red

Question 34

Cu(OH)₂ colour

Answer 34

pale blue preceip

Question 35

Fe(OH)₂ colour

Answer 35

green (goes brown in air) precip

Question 36

Fe(OH)₃ colour

Answer 36

brown precip

Question 37

what is a d block element?

Answer 37

highest energy electron in the d block (in a d-subshell)

Question 38

colour of Co(OH)₂

Answer 38

blue (beige in air) precip

Question 39

requirement for optical isomer of a complex ion?

Answer 39

• 3 bidentate ligands
• 2 bidentate 2 mono dnetate
• one hexadentate

Question 40

colour of [CoCl₄]

Answer 40

blue