This page contains the AQA A2 Reaction Of Inorganic Compound In Aqueous Solution Questions and kerboodle answers for revision and understanding .This page also contains the link to the notes and video for the revision of this topic.
C24.1 The acid-base chemistry of aqueous transition metal ions AQA A2 Chemistry C24 Reaction Of Inorganic Compound In Organic Solution Kerboodle Answers : Page No. 128
1 a MnO4–
+7
b crO42-
+6
c cr2O72-
+6
2
Acid-base. Il is not redox as the chromium is in the +6 state before and after. One of the oxygen atoms accepts two protons (H+ ions).
24.2 Ligand substitution reactions AQA A2 Chemistry C24 Reaction Of Inorganic Compound In Organic Solution Kerboodle Answers : Page No. 131
1
2 a
b Bromide ions are bigger than water molecules, so fewer can fit around the copper ion. The shape is tetrahedral.
3
At each step two entities produce three, therefore the entropy change of each step is likely to be positive.
4
No, it remains at +2.
b
[Co(H2O)6]2+ is octahedral and [CoCI4]2- is tetrahedral.c
The ligands have changed as has the co-ordination number.
24.3 A summary of acid-base and substitution reactions of some metal ions AQA A2 Chemistry C24 Reaction Of Inorganic Compound In Organic Solution Kerboodle Answers : Page No. 133
1 They are smaller and more highly charged and therefore more strongly polarising. They can thus weaken one of the 0-H bonds in one of the water molecules that surround them, so releasing a H+ ion.
2 Aluminium is not a transition metal. It has no pan-filled d-orbitals. Most transition metal compounds arc coloured because of the electrons moving between pan-filled d-orbitals that absorb light.
3 Both NH3 and H2O are of similar size and are neutral ligands.
4 a
i
ii
b a i
The orange brown solution changes to a reddish brown solid.
ii?
The pale blue solution turns to dark blue.
Banner 2Practice questions: Page No.
1
(a)
N in Cu(NO3)2 oxidation state: +5
N in NO2 oxidation state: +4
Oxidation product: oxygen
(b)
[Cu(H2O)6]2+Octahedral
(c)
Cu(H2O)4 (OH)2 OR Cu(OH)2
[Cu(H2O)6]2+ + 2NH3 → Cu(H2O)4 (OH)2 + 2NH4+(d)
[Cu(NH3)4(H2O)2]2+ deep blue Cu(H2O)4(OH)2 + 4NH3 → [Cu(NH3)4(H2O)2]2+ + 2H2O + 2OH– |
(e)
[CuCl4]2-Yellow-green
Tetrahedral
(f) (i)
1s2 2s2 2p6 3s2 3p6 3d10
(ii) A reducing agent
2 (a)
Forms blue or pink precipitate.
Co(H2O)4 (OH)2
Precipitate dissolves in excess ammonia.
Forms yellow or pale brown ‘straw’ coloured solution.
[Co(NH3)6]2+Darkens on standing in air.
[Co(NH3)6]3+ formed.Due to oxidation by O2 in air.
(b)
Fe3+ has a larger charge and smaller size than Fe2+.
The Fe3+ polarises a ligand water molecule to a greater extent.
The solution of Fe3+ contains more H+ ions.green precipitate with Fe2+
FeCO3
brown or red/brown precipitate with Fe3+
[Fe(H2O)3(OH)3]Effervescence as carbon dioxide is evolved from the Fe3+ reaction.
3
(a)
Reaction 1
Ammonia (NH3) (solution) / NaOH
(b)
Reaction 2
Ammonia (conc/xs)
[Cu(H2O)4(OH)2] + 4NH3 → [Cu(H2O)2(NH3)4]2+ + 2H2O + 2OH–(c)
Reaction 3
Na2CO3 / any identified soluble carbonate /
NaHCO3
(d)
Reaction 4
HCl (conc/xs) / NaCl
[Cu(H2O)6]2+ + 4Cl– → [CuCl4]2- + 6H2O4
(a)
W is CuCl42-
Yellow-green/yellow/green
[Cu(H2O)6]2+ + 4Cl– → CuCl42- + 6H2O(b)
X is Cu(H2O)4(OH)2
Blue precipitate/solid
[Cu(H2O)6]2+ + 2NH3 → Cu(H2O)4(OH)2 + 2NH4+(c)
Y is [Cu(NH3)4(H2O)2]2+
Deep/dark/royal blue solution
Cu(H2O)4(OH)2 + 4NH3 → [Cu(NH3)4(H2O)2]2+ + 2H2O + 2OH–
(d)
Z is CuCO3
Green solid/precipitate
[Cu(H2O)6]2+ + CO32- → CuCO3 + 6H2O(e) (i)
Cu2+(aq) + Fe(s) → Cu(s) + Fe2+(aq)
Blue
Green
(ii)
Any two correct points about copper extraction from two of these three categories:
Any relevant mention of lower energy consumption
Any relevant mention of benefits of less mining (of copper ore)
Less release of CO2 (or CO) into the atmosphere
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