ChemistryCode 9701
Periodicity of chemical properties of the elements in Period 3
What this topic asks you to be able to do
- describe what happens when each element reacts with oxygen (forming Na2O, MgO, Al2O3, P4O10 or SO2), with chlorine (forming NaCl, MgCl2, AlCl3, SiCl4 or PCl5) and with water (Na and Mg only), giving equations for these reactions
- state and explain how oxidation number changes across the oxides (only Na2O, MgO, Al2O3, P4O10, SO2 and SO3) and the chlorides (only NaCl, MgCl2, AlCl3, SiCl4, PCl5), explained by the electrons in their outer (valence) shell
- describe the oxides Na2O, MgO, Al2O3, SiO2, P4O10, SO2 and SO3 as they react with water, if they react at all, and give equations for these reactions, including the probable pHs of the solutions formed
- describe and explain how the oxides Na2O, MgO, Al2O3, P4O10, SO2 and SO3, and the hydroxides NaOH, Mg(OH)2 and Al(OH)3, behave as acids or bases, writing equations for this, including any amphoteric behaviour when they react with acids and bases (sodium hydroxide only)
- describe and account for what happens when the chlorides NaCl, MgCl2, AlCl3, SiCl4 and PCl5 are added to water, write equations for these reactions, including the probable pHs of the solutions produced
- explain the trends and variations described in 9.2.2, 9.2.3, 9.2.4 and 9.2.5 by reference to bonding and electronegativity
- suggest, from what is observed of their chemical and physical properties, which kinds of chemical bonding the chlorides and oxides contain