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A2 Chemistry Unit 2 > Transition Metals > Flashcards

Flashcards in Transition Metals Deck (32)
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1

What is the definition of a transition metal

An element which forms at least one stable ion with a partially filled d subshell

2

What is a complex

A central atom or ion with ligands bonded by coordinate bonds

3

What is a ligand

An ion or molecule with a lone pair of electrons which forms a coordinate bond with a central metal atom or ion in a complex

4

What is a coordination number

The number of coordinate bonds to a central metal atom or ion in a complex

5

What is a monodentate ligand

A ligand which uses only one lone pair of electrons to form a coordinate bond with a central metal atom or ion

6

What is a polydentate ligand

A ligand which uses many lone pairs of electrons to form more than two coordinate bonds with a central metal atom or ion in a complex

7

What is the definition of a bidentate ligand

A ligand which uses two lone pairs of electrons to form two coordinate bonds with a central metal atom or ion in a complex

8

What are the properties of transition metals

Hard
High mp
High density
Form complexes
Form coloured aqua
Compounds with varying oxidation states
Metal + ion acts as catalyst

9

Describe the increase in IE across transition series

- 3d lower in energy than 4s
- transition metal formed by addition of electron to inner 3d
- electron added to inner shell means better shielding of outer 4s electrons from the increased positive nuclear charge
- atomic radius shows only a small decrease

10

What is the general formula of a complex

See notes

11

What is the charge of the complex if the ligand is neutral

The charge = the O.N of the metal

12

What is the charge if the ligand is anionic

ON of metal + (no. Of ligands x charge of ligand)

13

What does the chelate effect mean

Increase in entropy means replacement will happen

14

What is the order of stability in ligands

H2O < Cl4 < NH3 < en < edta

15

Name the four ions that are green

Cr^3+
V^3+
Fe^2+
Ni^2+

16

What are the two yellow metal ions

Chromate (VI) ➡️ CrO4^2-
V(V) ➡️ VO2^+

17

What are the two pink metal ions

Mn^2+
Co^2+

18

What are the two blue metal ions

Cu^2+
V(IV) (VO^2+)

19

What is the violet metal ion

V^2+

20

What are the two orange metal ions

Dichromate (VI) ➡️ Cr2O7^2+
Fe^3+

21

What is the colour change when zinc reduces ammonium vanadate (V) in conc HCl

Yellow ➡️ blue ➡️ green ➡️ violet

22

Draw the structure of edta

See notes

23

Draw the structure of en

See notes

24

Describe the strength of the en ligand

Two N containing lone pairs
Alkyl group pushes e away
Small amount of extra negative charge on N
Makes lone pair more available
Stronger ligand

25

Describe the strength of the phenylamine ligand

Weaker in strength
Lack of intense charge around N
Need to break some delocalisation

26

What colour is the precipitate of (Cr(H2O)6)^3+ and what colour is it in NaOH and NH3

Blue green
Green (Cr(OH)6)^3- (aq)
Not soluble so stays same as start

27

What colour is the precipitate of (Mn(H2O)6)^2+ and what colour is it in NaOH and NH3

White which darkens to brown/black on standing
Not soluble
Not soluble

28

What colour is the precipitate of (Fe(H2O)6)^2+ and what colour is it in NaOH and NH3

Green
Not soluble
Not soluble

29

What colour is the precipitate of (Fe(H2O)6)^3+ and what colour is it in NaOH and NH3

Brown
Not soluble
Not soluble

30

What colour is the precipitate of (Co(H2O)6)^2+ and what colour is it in NaOH and NH3

Blue
Not soluble
Yellow (changes to brown on standing) (Co(NH3)6)^2+ (aq)