These are detailed Revision Notes for Topic 2.6 of AQA A-Level Chemistry (Reactions of Inorganic Compounds in Aqueous Solution). They were written by me using a combination of the textbook and class notes. I will also be uploading the other topics and creating bundles.
Topics Included:
- The aci...
Reactions of Inorganic Compounds in Aqueous Solutions
24.1 The Acid-Base Chemistry of Aqueous Transition Metal Ions:
24.1 the acid-base chemistry of aqueous
- Metal ions become hydrated in water with H2O ligands
around the metal ion transition metal ions
- Metal 3+ ions are more acidic than 2+ ions. This is because 24.2 ligand substitution reactions
they have a greater charge density and so have a higher
polarising power. 24.3 a summary of acid-base and
- As charge density increases the cation has a greater substitution reactions of some metal ions
attraction for water, this pulls the electron pair in the O-H
bond towards the O. This makes the H more acidic.
- Water acts as a Lewis Base and the metal ions act as Lewis bases.
- Some substances can show both acidic and basic properties, these are called amphoteric. Aluminium is an
example of an amphoteric hydroxide.
o Al(H2O)3(OH)3 + 3HCl à Al(H2O)63+ + 3Cl-
o Al(H2O)3(OH)3 + OH- à [Al(OH)4]- + 3H2O
Reactions with Sodium Hydroxide:
- The hydroxide group takes a proton from the water ligand leaving a hydroxide group in the complex and
forming water. This continues until the complex is neutral, it forms a solid and drops out of solution, a
precipitate will form.
- [Fe(H2O)6]2+(aq) + 2OH- à Fe(H2O)4(OH)2(s) + 2H2O(l)
- [Cu(H2O)6]2+(aq) + 2OH- à Cu(H2O)4(OH)2(s) + 2H2O(l)
- [Fe(H2O)6]3+(aq) + 3OH- à Fe(H2O)3(OH)3(s) + 3H2O(l)
- [Al(H2O)6]3+(aq) + 3OH- à Al(H2O)3(OH)3(s) + 2H2O(l)
o If more sodium hydroxide is added in excess aluminium can undergo a further reaction to form
[Al(OH)4]-
o Al(H2O)3(OH)3(s) + OH- à [Al(OH)4]-(aq) + 3H2O(l)
Reactions with Ammonia:
- Reactions with ammonia work in the same was as with sodium hydroxide, precipitates will form and drop
out of solution
- [Fe(H2O)6]2+(aq) + 2NH3(aq)à Fe(H2O)4(OH)2(s) + 2NH4+(aq)
- [Cu(H2O)6]2+(aq) + 2NH3(aq)à Cu(H2O)4(OH)2(s) + 2NH4+(aq)
o If excess is added a further step occurs
o Cu(H2O)4(OH)2(s) + 4NH3(aq) à [Cu(H2O)2(NH3)4]2+(aq)+ 2OH-(aq) + 2H2O(l)
- [Fe(H2O)6]3+(aq) + 3NH3(aq)à Fe(H2O)3(OH)3(s) + 3NH4+(aq)
- [Al(H2O)6]3+(aq) + 3NH3(aq)à Al(H2O)3(OH)3(s) + 3NH4+(aq)
Reactions with Sodium Carbonate:
- Carbonate ions react differently depending on the oxidation state.
- A precipitate will form, and, in the 3+ reactions CO2 is produced
- The greater acidity of 3+ metal ions means that the carbonate will act as a base and remove protons.
- [Fe(H2O)6]2+(aq) + CO32-(aq) à FeCO3(s) + 6H2O(l)
- [Cu(H2O)6]2+(aq) + CO32-(aq) à CuCO3(s) + 6H2O(l)
- [Fe(H2O)6]3+(aq) + 3CO32-(aq) à Fe(H2O)3(OH)3(s) + 3CO2(g) + 3H2O(g)
- [Al(H2O)6]3+(aq) + 3CO32-(aq) à Al(H2O)3(OH)3(s) + 3CO2(g) + 3H2O(g)
24.2 Ligand Substitution Reactions:
- Complexes containing water molecules can have the water ligands replaced by different ligands.
- Replacement by water or ammonia ligands do not involve a change in coordinate number as they are a
similar size.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller emilysarahjudge. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £2.99. You're not tied to anything after your purchase.
