Module 5: Transition metals

Question 1

What is a transition element?

Answer 1

A d-block element that has an incomplete d-sub-shell as a stable ion.

Question 2

What catalysts are used in:
1. Haber process
2. Contact Process
3. Hydrogenation of alkenes.
4. Decomposition of hydrogen peroxide.
5. Hydrogen production 
Give the equations for the reactions.

Answer 2

1. Iron metal N2 + 3H2 —> 2NH3
2. Vanadium oxide (V2O5) 2SO2 + O2 —> 2SO3
3. Nickel metal C2H4 + H2 —> C2H6
4. Manganese (IV) oxide MnO2 2H2O –> 2H2O + O2
5. Copper (II) sulphate Zn + H2SO4 —> ZnSO4 + H2

Question 3

What colour are Cu2+ ions in solution.

what happens upon the addition of NaOH?

Answer 3

Solution = blue
NaOH = light blue ppt

Question 4

What colour are Co2+ ions in solution.

what happens upon the addition of NaOH?

Answer 4

Solution = pink
NaOH = dark blue ppt

Question 5

What colour are Fe3+ ions in solution.

what happens upon the addition of NaOH?

Answer 5

Solution = Rust
NaOH = rust coloured ppt

Question 6

What colour are Fe2+ ions in solution.

what happens upon the addition of NaOH?

Answer 6

Solution = Grey/green
NaOH = Grey/green ppt

Question 7

What colour are Ni2+ ions in solution.

what happens upon the addition of NaOH?

Answer 7

Solution = Green
NaOH = Light green ppt

Question 8

What colour are Zn2+ ions in solution.

what happens upon the addition of NaOH?

Answer 8

Solution = Colourless
NaOH = White ppt

Question 9

How do you form precipitates?

Answer 9

Precipitates are formed when an insoluble solid forms from 2 solutions.

Question 10

Define a complex ion.

Answer 10

Transition metal bonded to one or more ligands by coordinate bonds.

Question 11

Define ligands.

Answer 11

Molecule or ion that can donate a pair of electrons to the transition metal ion to form a coordinate bond.