Transition metals

Question 1

What is the definition of a transition metal?

Answer 1

elements in the d block of the periodic table that can form at least one stable ion with an incomplete d sub-shell

Question 2

Why is Sc not a transition metal?

Answer 2

it only forms one ion (Sc3+) and it has an empty d subshell, doesn’t meet the requirements of a partially filled d subshell

Question 3

Why is Zn not a transition metal?

Answer 3

it only forms one ion (Zn2+) and it has a full d subshell which doesn’t meet the requirements of a partially filled d subshell

Question 4

What are properties of transition metals?

Answer 4

(1) can form ions with different oxidation states (ie Fe2+, Fe3+)
(2) can form coloured ions
(3) can be used as catalysts

Question 5

What are some examples of transition metals that can be used as catalysts?

Answer 5

• Fe in the haber process
• Manganese dioxide (MN02) in decomposition of hydrogen peroxide
• Vanadium pentoxide (V2O5) catalyses the contact process

Question 6

What is a complex ion?

Answer 6

an ion that is surrounded by coordinately bonded ligands

Question 7

What is a ligand?

Answer 7

an atom, ion / molecule that donates its lone pair of electrons to form a coordinate bond with a central metal ion

Question 8

What is a bidente ligand?

Answer 8

donates 2 lone pair of electrons to a metal ion to form 2 coordinate bonds to a metal ion

Question 9

How do you work out the charge of a complex ion?

Answer 9

• if all ligands are neutral, charge of complex ion is same as charge on central metal ion
• if ligands contain a charge (subtract/ add this number to the charge of central metal ion)