5. Reactions of ions Flashcards
interconversion betweenFe2+ and Fe3+
Fe2+ is oxidised to Fe3+ by which solution?
acidified potassium manganate (VII)
KMnO4(aq)
interconversion betweenFe2+ and Fe3+
Fe3+ is reduced to Fe2+ by which ions?
Iodide ions
I-(aq)
Interconversion between Cr3+ and Cr2O7 2-
Cr3+ ion in [Cr(OH)6]3- is oxidised to CrO42- by what solution and conditions>
(Cr3+ -> Cr6+)
warming with hydrogen peroxide solution H2O2(aq)
in alkaline conditions
Interconversion between Cr3+ and Cr2O7 2-
Cr2O7 2- is reduced to Cr3+ by what solution?
(Cr6+ -> Cr3+)
acidified zinc
Reduction of Cu2+ (Cu2+ -> Cu+)
- Cu2+ is reduced to CuI by which ions?
- equation
- Iodide ions I-
2. 2Cu2+(aq) + 4I-(aq) -> 2CuI(s) + I2(aq)
Equation for disproportionation of Cu+
2Cu+(aq) -> Cu(s) and Cu2+(aq)
identifying transition elements adding NaOH(aq) dropwise
Cu2+ observation
blue precipitate
identifying transition elements adding NaOH(aq) dropwise
Fe2+ observation
green precipitate
identifying transition elements adding NaOH(aq) dropwise
Fe3+ observation
orange precipitate
identifying transition elements adding NaOH(aq) dropwise
Mn2+ observation
pink/buff precipitate
identifying transition elements adding NaOH(aq) dropwise
Cr3+ observation
grey-green precipitate
Common ligands.
CO3 2- (carbonate)
1. test
2. observation
- add nitric acid. bubble any gas given off through limewater.
- lime water turns from clear to cloudy if carbonate present (CO2(g))
Common ligands.
CO3 2- (carbonate)
1. test
2. observation
- add silver nitrate
2. white precipitate
Common ligands.
Br- (bromide)
1. test
2. observation
- add silver nitrate
2. cream precipitate
Common ligands.
I- (iodide)
1. test
2. observation
- add silver nitrate
2. pale yellow precipitate
Common ligands.
SO4 2- (sulfate)
1. test
2. observation
- add barium nitrate Ba(NO3)2 OR barium chloride BaCl2
2. white precipitate
Common ligands.
NH4+ (ammonium)
1. test
2. observation
- add cold NaOH and warm. hold damp red litmus paper over solution
- red litmus paper turns blue in presence of ammonia.
why use HNO3 instead of HCl in the test for carbonates?
HCl would add chloride ions to sample.
can’t tell wether the initial sample contained chloride ions (deffo get white precipitate with silver nitrate)
