Transition Metals Flashcards
Define what is meant by a transition element.
a d-block element that can form at least one stable ion with a partially filled d subshell
State and explain the two exceptions when deducing electron configurations.
- copper and chromium
- adjusted to make the d-orbital fully filled or half filled
Explain why zinc and scandium are not considered transition metals.
- scandium only forms a 3+ ion which has an empty d subshell
- zinc 2+ ions have a full d subshell
State what is meant by a complex ion
a central transition metal ion surrounded by ligands bonded by co-ordinate bonds
State what is meant by a ligand.
an ion/molecule that has at least one lone pair of electrons and forms a dative bond with a transition metal ion
State the shapes of the molecules with co-ordination number:
- 6
- 4
- 2
6 → octahedral
4 → tetrahedral (or square planar)
2 → linear
Describe the structure of haem.
→ multidentate ligand
→ consists of 4 groups
→ bonded to Fe ion through co-ordinate bonds
State what is meant by a bidentate ligand.
a ligand that has two lone pairs (from two different atoms)
how many bonds does EDTA⁴⁻ form?
6
Give two examples of a bidentate ligand.
→ ethanedioate
→ ethane-1,2-diamine
State which complexes show optical isomerism.
octahedral complexes with bidentate ligands
State which complexes show cis-trans isomerism
- octahedral complex that has:
→ 4 ligands of same type
→ two ligands of another type - square planar complexes
Explain what is meant by the chelate effect.
→ monodentate ligands are replaced by multidentate ones
→ this increases entropy (more moles on products side)
→ higher entropy = more -ive ΔG meaning reaction is more feasible
State the equation relating energy and frequency.
ΔE = hf
What is the effect of increasing ΔE on frequency absorbed?
large ΔE = higher frequency absorbed
( therefore lower frequency observed)
