Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Chemistry > Reactions of inorganic compounds in aq > Flashcards

Reactions of inorganic compounds in aq Flashcards

1
Q

Lewis theory of acids

A

Electron pair acceptors in the formation of co-ordinate bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Lewis theory of bases

A

Electron pair donors in the formation of co-ordinate bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why is the Lewis definition of acids wider than the Bronsted-Lowry one?

A

Bronsted-Lowry applies only to exchange of protons so compounds have to contain hydrogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Aqua ions

A

6 water molecules act as ligands bonding to the metal ion in an octahedral arrangement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why is Fe3+ (aq) acidic at all and why the difference with Fe2+(aq)?

A

The Fe3+ ion is both smaller and more highly charged than Fe2+, making it more strongly polarising. So in the [Fe(H2O)6]3+ ion the iron strongly attracts electrons from the oxygen atoms of the water ligands, thus weakening the O-H bonds in of the water molecules. This complex ion will then readily release an H+ making the solution acidic. Fe2+ is less polarising and hence less O-H bonds break in solution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Hydrolysis reaction

A

O-H bonds are broken and a new species are formed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How to distinguish between Fe2+ and Fe3+ in aq

A

[Fe(H2O)6]2+ = pale green
[Fe(H2O)6]3+ = pale brown
Add dilute alkali, which precipitates the hydroxides whose colours are more obviously different.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Reactions with the base CO32-

A

In general, carbonates of transition metal ions in oxidation state +2 exist, while those of ions in the +3 state don’t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

2 Amphoteric hydroxides

A

Al(H2O)3(OH)3 + Cr(H2O)3(OH)3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

CrO42-

A

Yellow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Cr2O72-

A

Orange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How can water molecules acting as ligands be replaced by other ligands?

A
  1. Other ligands form stronger co-ordinate bonds (better Lewis bases)
  2. Present in higher conc. and an equilibrium is displaced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

[Co(H2O)4(OH)2]

A

Blue precpitate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens if more conc. NH3 is added to [Co(H2O)4(OH)2]?

A

Both OH- and all 4 water ligands are replaced by ammonia because :

  1. Ammonia is a better ligand than water
  2. High conc. of ammonia displaces equilibria, displacing water and OH-
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Observations if more conc. NH3 is added to [Co(H2O)4(OH)2]

A

The blue precipitate dissolves to form a pale yellow solution which is oxidised by oxygen in air to a brown mixture with Co(III)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

[Cu(H2O)6]2+ + 4NH3

A

[Cu(NH3)4(H2O)2]2+ pale blue to very deep blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Shape of [Cu(NH3)4(H2O)2]2+

A

Octahedral, 4 NH3 square planar arrangement with H2O above and below. Cu-O bonds are longer and weaker than Cu-N

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

[Cu(H2O)6]2+ + 4Cl-

A

[CuCl4] 2-, Pale blue replaced by yellow [CuCl4]2- -> co-ordinate number 6-> 4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Chelation

A

Formation of complexes with multidentate ligands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why do multidentate ligands form more stable complexes than monodentate ligands?

A

Entropy change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

[Fe(H2O)6]2+

A

Pale green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

[Co(H2O)6]2+

A

Pink

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

[Cu(H2O)6]2+

A

Pale blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

[Al(H2O)6]3+

A

Colourless

25
Q

[V(H2O)6]3+

26
Q

[Cr(H2O)6]3+

A

Pale green

27
Q

[Fe(H2O)6]3+

28
Q

Deprotonation

A

The loss of a proton by a water ligand to form a hydroxo ligand

29
Q

Fe(OH)2

30
Q

Co(OH)2

31
Q

Cu(OH)2

32
Q

Al(OH)3

33
Q

Cr(OH)3

A

Green/grey

34
Q

Fe(OH)3

35
Q

Al(OH)63-

A

Colourless

36
Q

Cr(OH)63-

37
Q

FeCO3

A

Green ppt 2+ / Brown ppt 3+

38
Q

CoCO3

39
Q

CuCO3

A

Green-Blue ppt

40
Q

[Co(OH)2(H2O)4]

41
Q

[Co(NH3)6]2+

42
Q

[Co(NH3)6]3+

43
Q

[Cu(NH3)4(H2O)2]2+

44
Q

CoCl42-

45
Q

CuCl42-

A

Green/yellow

46
Q

The chelate effect

A

The entropy of the system thus increases, and multidentate complexes are therefore more stable than complexes involving monodentate ligands.

47
Q

VO2+

48
Q

CrCO3

A

Pale green ppt

49
Q

CoCO3

50
Q

AlCO3

51
Q

3 changes to a transition-metal complex which result in a change in colour

A
  1. Oxidation states
  2. Ligands
  3. Co-ordination number
52
Q

Outline a plan for experiments which would enable you to determine the conc. of a transition metal ion in a solution of unknown conc.

A
  1. Add appropriate ligand to intensify colour
  2. Make up solutions of known conc.
  3. Measure absorption
  4. Plot graph of results
  5. Measure absorption of unknown + compare
53
Q

Linear complex formed when an excess of conc. HCl is added to silver chloride

54
Q

Reagents for VO2+ -> [V(H2O)6]2+

55
Q

Reagent for {Ag(NH3)2]+ -> Ag

56
Q

Reagent for [Cr(H2O)6]3+ -> CrO42-

A

H2O2, NaOH

57
Q

Describe an experiment to show that vanadium has several oxidation states

A
  1. Xs Zn, HCl
  2. Absence of air
  3. Colours seen
  4. V(IV), V(III), V(II) seen
58
Q

2 equations to show that chromium (III) hydroxide is amphoteric

A
  1. Cr(OH)3 + 3H+ -> [Cr(H2O)6]3+

2. Cr(OH)3 + 3OH- -> [Cr(OH)6]3-

Chemistry (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions