Transition metals (P1+P3) Flashcards
What is a transition metal?
Forms at least one stable ion with a partially filled d-subshell
Which 2 elements are not transition metals and why?
Scandium as it only forms Sc3+
Zinc as it only forms Zn2+
What features do transition metals display?
form complex ions
form coloured ions
display catalytic properties
have variable oxidation states
What is a ligand?
a molecule which can donate a lone pair of electrons that can form a coordinate bond with a transition metal ion.
What is a bidentate ligand?
A ligand that has 2 separate atoms. Each atom has a pair of electrons available to form a coordinate bond.
What is a coordination number?
number of coordinate bonds a TM forms
What is a complex ion?
Central atom surrounded by ligands.
What is a monodentate ligand?
forms one coordinate bond only.
Give 2 examples of bidentate ligands
- Ethane-1,2-diamine
- Ethanedioate
How many coordinate bonds can EDTA^4- form?
6 in total;
- 2 from the Nitrogen’s in the middle
- 4 from the Oxygens on the end.
What is the chelate effect?
- when monodentate ligands are replaced by fewer multidentate ligands.
- there is always an entropy
[Cu(NH3)6]2+ + 3H2NCH2CH2NH2 –> [Cu(H2NCH2CH2NH2)3]2+ + 6NH3
Explain why this reaction is feasible?
- enthalpy change is 0
- number of Cu-N bonds broken and formed is equal.
- 7 moles are formed from 4 moles.
- there is a large increase in entropy.
- delta G = negative.
What is haemoglobin made up of?
4 coordinate bonds between Fe2+ and nitrogen atoms in haem
- 1 coordinate bond
