WorksheetsTransition metal ion colours and oxidation states
Total questions: 28
Worksheet time: 45mins
A blue solution that turns green-yellow on adding conc HCl contains
Fe3+
Cu2+
Fe2+
Mn2+
A green precipitate that is unchanged on adding excess NaOH contains
Cr3+
Fe2+
Mn2+
Cu2+
A green precipitate that dissolves to form a dark green solution on adding excess NaOH contains
Fe3+
Mn2+
Cu2+
Cr3+
A yellow solution that forms an orange precipitate on adding ammonia solution contains
Fe3+
Fe2+
Mn2+
Cu2+
A pale pink solution has ammonia solution added to it. It forms a light brown precipitate that gradually darkens. The precipitate is:
[Cr(NH3)6]3+
[Mn(NH3)6]2+
Cr(OH)3
Mn(OH)2
A green solution forms a green precipitate when a little ammonia solution is added to it. What will happen when excess ammonia solution is added?
The precipitate will dissolve to become a dark green solution.
The precipitate will dissolve to become a purple solution.
No change.
The precipitate will dissolve to become a deep blue solution.
A blue solution produces a blue precipitate with a little ammonia solution. What happens with excess ammonia solution?
No change
The precipitate dissolves to give a yellow solution
The precipitate dissolves to give a purple solution.
The precipitate dissolves to give a deep blue solution.
What is the likely formula of an orange precipitate?
Fe(OH)3
Fe(OH)2
Mn(OH)2
Cr(OH)3
A green precipitate that does not change with excess NaOH is:
Cr(OH)3
Fe(OH)2
Fe(OH)3
Mn(OH)2
The precipitates formed when ammonia is added to a transition metal hexaaqua complex ion are:
new complexes formed when ammonia replaces the water ligands in a ligand replacement reaction
transition metal hydroxides formed in a precipitation reaction
the same colour as the original solution of the TM hexaaqua complex ion
all soluble in excess ammonia
Which of the following is NOT a chemical property of transition metal ions.
Formation of complex ion
Variable oxidation states
Different shapes
Formation of coloured complexes
Cobalt has a proton number of 27. Choose the correct electronic configuration for Co4+.
[Ar]3d34s2
[Ar]3d7
[Ar]3d74s2
[Ar]3d5
Which of the transition elements exhibit highest oxidation state?
Manganese
Vanadium
Iron
Chromium
Which of the following species is not a ligand?
Hydrogen
Ammonia
Fluorine
Water
Identify the shape for the complex ion of [Co(NH3)2(H2O)4]Cl2.
Tetrahedral
Square planar
Octahedral
Hexagonal
Most of the transition metals are good catalysts because
they are strong reducing agent.
they can vary their oxidation state
they are reactive
they able to form stable ion
Which one is not a colour exhibited by vanadium ions.
Violet
Green
Yellow
Orange
How many diaminoethane molecules substitute the water molecules in [Cu(H2O)6]2+?
1
2
3
4
How many EDTA4- ions substitute the water molecules in [Cu(H2O)6]2+?
1
2
3
4
What is the coordination number of this complex.
one because it has one EDTA ligand
4 because it has 4 coordinate bonds
6 because it has 6 coordinate bonds
2 because it has a 2- charge
which are true about the reaction (More than 1)
[Cu(H2O)6]2+ + EDTA2-—->[CuEDTA]2-+ 6H2O
the EDTA complex is energetically less stable
the EDTA complex is energetically more stable because of the chelate effect.
the entropy change is positive
2- complexes more stable than 2+
Identify the shape for the complex ion of Pt(NH3)2Cl2. Cis platin.
Tetrahedral
Square planar
Octahedral
Hexagonal
Which species of vanadium is the best OXIDISING agent?
V2+
V3+
VO2+
VO2+
Which species of vanadium is the best REDUCING agent?
V2+
V3+
VO2+
VO2+
