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.

16.2 - Group 3 (13)

Candidates should be able to:

(e) understand the electron deficient nature of Group 3 systems such as BF3, BCl3 and monomeric AlCl3 and their electron acceptor properties;

(f) explain the ready formation of the Al2Cl6 dimer, its structure and its bonding;

(g) understand the formation of donor-acceptor compounds such as NH3.BF3;

(h) recall that the affinity of AlCl3 for chlorine species results in industrially important catalysts such as

(i) explain how boron nitride, BN, forms hexagonal and cubic structures corresponding to graphite and diamond respectively and, because of its hardness, chemical inertness, high melting temperature and semiconductor properties, is finding increasing use as lubricant, as wear-resistant coating and as nanotubes for wire sleeving, catalyst support and semiconduction;

(j) recognise that in none of the cases (f) to (i) above is the compound electron deficient.