Transition Elements Flashcards
What is a transition metal?
They are elements which have an ion with an incomplete d subshell (between 1 and 9 e-), so have more than one oxidation state.
Why do Copper and Chromium have 4s1 rather than 4s2?
To get a half filled (3d5 in chromium) or filled (3d10 in copper) subshell. This is the most energetically stable electronic configuration.
Why is Scandium not a transition element?
None of its ions have an incomplete d subshell.
Why is Zinc not a transition metal?
It only forms 2+ ions where both electrons are lost from an s orbital. So it doesn’t form an ion with an incomplete d subshell, meaning it is full.
What are the properties of transition metals?
They have catalytic behaviour.
Variable oxidation states.
Form complex ions.
Form coloured compounds.
What is a comolex ion?
A molecule or ion consisting of a central metal atom or ion with a number of molecules or ions surrounding it.
What is the colour of iron 2+ solutions?
Pale greenW
What are the colour of iron 3+ solutions
Pale yello
What are the colour of Manganese 2+ ions in solution?
Pale pink
What transition metal is used as a catalyst in the harber process?
Fe, iron
Where is nickel used as a catalyst?
In the hydrogenation of alkenes to alkanes
What is a ligand?
A species whose lone pair is coordinated to a metal ion in a complex ion
What shape do 6 ligands in a complex ion form?
Octahedral (90 degrees)
What is the shape of a complex ion with 4 ligans and why do they only have 4?
Eg Cl2, it is large so only four can fit around the ion.
The shape is tetrahedral (109.5 degrees)
What is the coordination number of a complex ion?
The number of lone pairs coordinated to the ion. Some molecules can donate 2 pairs of electrons.
