Identify all the species in the table which could convert I–aq) into I2(aq) but which could not convert Br–(aq) into Br2(l).

• Fe3+ ; (1) NO3– (1)

EOMT next Tuesday

Transition metals

L.O.: Deduce the electron configurations of atoms and ions of the d-block elements.

Describe the elements Ti–Cu as transition elements.

First row of the transition metal block

Energy-level diagram showing the overlap of the 3d and 4s sub-shells

Tip: 4s orbital is filled before 3d, but 4s electrons are removed before any electrons are taken out from the 3-d sub-shell.

Write electronic configurations of: Sc, Ti, Cu and Zn.

To which block of the periodic table do Sc, Ti and Cu belong to? Why?

Write the electronic configurations of Sc3+, Zn2+, Cu+ and Cu2+.

Why Sc and Zn are not transition metals?

A transition element is a d-block element that forms an ion with an incomplete d sub-shell

• Give the electronic configuration of the following atoms:

a) Vb) Crc) Co

• d) Cu• e) Zn

• 2. Give the electronic configuration of the following ions:

• • a) Co2+

• b) Cu+

• c) V3+

• d) Cr3+

• e) Fe3+

L.O.:

Illustrate the existence of more than one oxidation state for a transition element in its compounds.

Illustrate the formation of coloured metal ions.

Properties of transition metals

List all of the properties metals exhibit :• Good conductors of heat and electricity• High melting and boiling points• Malleable• Ductile• Shinny • Usually strong (high tensile and compressive strength)• Ions are usually brightly coloured• Often can be used when in compounds or as metals as

a catalyst

Oxidation numbers and colours of the common d block metal ions

Catalysis and precipitation

Illustrate the catalytic behaviour of the transition elements and/or their compounds.

Describe the simple precipitation reactions of Cu2+ (aq), Co2+(aq), Fe2+(aq) and Fe3+(aq) with aqueous sodium hydroxide.

Hydrogenation of the C=C bond in alkenes

Catalytic properties of transition metals

Two main causes for their catalytic properties• They can provide a solid surface onto which

the reactant can ADSORB and thereby hold it in place

• Their variable oxidation state allows them to form intermediates with reactants that lowers the activation energy of the reaction

Catalysts dependent on transition metals

• Catalytic converters – use platinum, rhodium and palladium

• Haber process uses iron• Hydrogenation of alkenes uses nickel metal• Decomposition of hydrogen peroxide uses

MnO2 • CONTACT PROCESS uses vanadium (V) oxide

to convert sulfur dioxide into sulfur trioxide which is needed to make sulfuric acid

Precipitating out transition metal ions• Transition metals in aqueous solution can be precipitated out using

NaOH(aq) to produce a insoluble transition metal hydroxide

• Write out the balanced equation for each of these metals