Reactions Of Inorganic Compounds In Aqueous Solution Flashcards
What is a Lewis acid?
Electron pair acceptor
What is a Lewis base?
Electron pair donor
When you form a complex ion, is the ligand a Lewis acid or base? Why?
Lewis base because it donates a pair of electrons in the dative covalent bond
Which part of a complex ion is a Lewis acid?
The metal ion
Why are 3+ metal ions more acidic than 2+?
3+ metal ions have a higher charge density
So they have a greater polarising power, which more strongly attracts the water molecule
This weakens the O-H bond so it breaks more easily, releasing H+ ions
Write the equilibrium reaction that would happen with [M(H2O)6]2+ and water
What metal could you use and state its colour?
[M(H2O)6]2+ + H2O <–> [M(H2O)5(OH)]+ + H3O+
Fe (green)
Cu (blue)
Write the equilibrium reaction that would happen with [M(H2O)6]3+ and water
Which metals could you use for this reaction and state its colour?
[M(H2O)6]3+ + H2O <–> [M(H2O)5(OH)]2+ + H3O+
Al (colourless)
Fe (violet)
State the reaction between [Cu(H2O)6]2+ and limited hydroxide
State the colour change
[Cu(H2O)6]2+ + 2OH- –> Cu(H2O)4(OH)2 + 2H2O
Blue solution –> blue precipitate
When an aqueous metal ion complex reacts with limited OH- or NH3, what type of product is formed?
Solid precipitate
Reaction between [Fe(H2O)6]2+ and limited ammonia
State the colour change
[Fe(H2O)6]2+ + 2NH3 –> Fe(H2O)4(OH)2 + 2NH4+
Green precipitate –> green precipitate
What would you observe if Fe(H2O)4(OH)2 was left standing in air?
Green precipitate would turn brown
Reaction between [Al(H2O)6]3+ and limited hydroxide
State the colour change
[Al(H2O)6]3+ + 3OH- –> Al(H2O)3(OH)3 + 3H2O
Colourless solution –> white precipitate
Reaction between [Fe(H2O)6]3+ and limited ammonia
State the colour change
[Fe(H2O)6]3+ + 3NH3 –> Fe(H2O)3(OH)3 + 3NH4+
Purple solution –> brown precipitate
Which metal ion complex can be further reacted with excess NaOH:
1) [Fe(H2O)6]2+
2) [Cu(H2O)6]2+
3) [Fe(H2O)6]3+
4) [Al(H2O)6]3+
4) [Al(H2O)6]3+
Reaction between [Al(H2O)6]3+ and excess OH- acting as a base
State the colour change
Step 1: [Al(H2O)6]3+ + 3OH- –> Al(H2O)3(OH)3 + 3H2O
Step 2: Al(H2O)3(OH)3 + OH- –> [Al(OH)4]- + 3H2O
Colourless solution –> white precipitate –> colourless solution
Reaction between [Al(H2O)6]3+ and excess OH- acting as an acid
State the colour change
Step 1: [Al(H2O)6]3+ + 3OH- –> Al(H2O)3(OH)3 + 3H2O
Step 2: Al(H2O)3(OH)3 + 3H+ –> [Al(H2O)6]3+
Colourless solution –> white precipitate –> colourless solution
What does amphoteric mean?
Can react and dissolve in both acids and bases
Which metal ion complex can be further reacted with excess ammonia?
1) [Fe(H2O)6]2+
2) [Cu(H2O)6]2+
3) [Fe(H2O)6]3+
4) [Al(H2O)6]3+
2) [Cu(H2O)6]2+
What is the reaction between [Cu(H2O)6]2+ and excess ammonia called?
Ligand substitution
Reaction between [Cu(H2O)6]2+ and excess ammonia
State thee colour changes
Step 1: [Cu(H2O)6]2+ + 2NH3 –> Cu(H2O)4(OH)2 + 2NH4+
Step 2: Cu(H2O)4(OH)2 + 4NH3 –> [Cu(NH3)4(H2O)2]2+ + 2H2O + 2OH-
Blue solution –> blue precipitate –> deep blue solution
In a reaction between [Cu(H2O)6]2+ and excess ammonia, what does the NH3 act as?
Lewis base (donates and electron pair)
What is the product of a 2+ ion reacting with carbonate?
MCO3 precipitate
What is the product of a 3+ ion reacting with carbonate?
M(OH)3 precipitate and CO2
Give the reaction between [Cu(H2O)6]2+ and carbonate
State the colour change
[Cu(H2O)6]2+ + CO3 2- –> CuCO3 + 6H2O
Blue solution –> blue/green precipitate
Reaction between [Fe(H2O)6]2+ and carbonate
State the colour change
[Fe(H2O)6]2+ + CO3 2- –> FeCO3 + 6H2O
Green solution –> green precipitate
What are reactions of a 2+ ion with carbonate classed as?
Precipitation reactions
What are reactions between a 3+ ion and carbonate classed as?
Acidity reactions
Reaction between [Fe(H2O)6]3+ and carbonate
State the colour change
2[Fe(H2O)6]3+ + 3CO3 2- –> Fe(OH)3(H2O)3 + 3H2O + 3CO2
Purple solution –> Brown precipitate
Reaction between [Al(H2O)6]3+ and carbonate ions
State the colour change
2[Al(H2O)6]3+ + 3CO3 2- –> Al(OH)3(H2O)3 + 3H2O + 3CO2
Colourless solution –> white precipitate
