Transition Metals Flashcards
What is a transition metal?
it forms at least one stable ion with a part-full d-shell of electrons.
Why are scandium and zinc not transition metals although they are in the d-block?
Scandium only formt eh ion Sc£+ which has an empty d-shell and zinc only forms Zn2+ which has a full d-shell.
Why are chromium and copper more sable than expected?
They only have one electron in the 4s outer shell. In chromium the d-shell is half-full and in copper it is full
What are the 4 main properties of transition metals?
- Form complex ions,
- Are coloured,
- Have variable oxidation states,
- Acts as catalysts.
What is a complex ion?
When 2, 4 or 6 ligands are bound to a transition metal.
What is the co-ordination number?
The number of ligands that surround the metal ion.
What is a multidentate ligand?
When there is more than one atom with a lone pair of electrons binding to the transition metal.
Give an example of a hexadentate ligand
EDTA 4-
What is the chelate effect?
When ligands are added to a solution of a transition metal salt with the result being more entities (an increase in entropy)
What is the shape of ions with a co-ordination number of 6?
Octehedral
What is the shape of ions with a co-ordination number of 4?
Tetrahedral and square planar
Why is there a difference in shape between [CoCl4]2- and [Co(NH3)6]3+?
The chloride ion is larger so only four Cl-‘s can fit around the meta ion whereas there is room for 6 NH3’s.
Give an example of a linear complex ion.
[Ag(NH3)2]+
What forms of isomerism do transition metals show?
Geometrical and optical.
When do transition metal complexes form optical isomers?
When they have 2 or more bidentate ligands.
