AS and A2 Chemistry notes and resources (WJEC specification) - UNIT CH5 Physical and inorganic chemistry

This unit develops ideas of redox, kinetics, energy changes and equilibria. The inorganic chemistry of some elements in various sections of the Periodic Table is studied.

TOPIC 17 'd' block transition elements

Candidates should be able to:

(a) recall that transition elements (except Cu) possess partly filled d-orbitals and derive the electronic configuration of any first row transition metal ion using a Periodic Table;

(b) recall that 4s electrons are lost more readily than 3d electrons in ion formation;

(c) explain why various oxidation states are possible in transition elements;

(d) recall that transition metals and their compounds are often good catalysts, give an example, and explain why this is so in terms of partially filled d-shells and variable oxidation states;

(e) recall that many complexes are formed by co-ordinate bonding between transition metal ions and ligands;

(f) describe the bonding, colour and formulae of the approximately octahedral complex ions [Cu(H2O)6]2+ and [Cu(NH3)4(H2O)2]2+ ,the approximately tetrahedral ion [CuCl4]2. ,and other complexes where relevant information is supplied;

(g)

(h) describe the reactions of Cr3+, Fe2+, Fe3+ and Cu2+ with excess aqueous . OH ; ¢Ó

(i) show an awareness of the economic importance of transition metals and their importance as trace elements in living systems, and give one example of economic importance and one example of trace element importance.

Note: *The simple electrostatic model is adequate to account for the d-orbital splitting. Candidates should be able appropriately to allocate electrons to the split d-orbitals using the arrows in boxes technique but consideration of the factors leading to high or low spin behaviour will not be required.