Physical Properties and Reactions of Period 3 Oxides

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PHYSICAL PROPERTIES OF THE PERIOD 3 OXIDES These pages explain the relationship between the physical properties of the oxides of Period 3 elements (sodium to chlorine) and their structures. Argon is obviously omitted because it doesn't form an oxide. A quick summary of the trends The oxides The oxides we'll be looking at are: |Na2O |MgO |Al2O3 |SiO2 |P4O10 |SO3 |Cl2O7 | | | | | |P4O6 |SO2 |Cl2O | Those oxides in the top row are known as the highest oxides of the various elements. These are the oxides where the Period 3 elements are in their highest oxidation states. In these oxides, all the outer electrons in the Period 3 element are…show more content…
What you can safely say is that because the metallic oxides and silicon dioxide have giant structures, the melting and boiling points are all high. Electrical conductivity Silicon dioxide doesn't have any mobile electrons or ions - so it doesn't conduct electricity either as a solid or a liquid. The molecular oxides Phosphorus, sulphur and chlorine all form oxides which consist of molecules. Some of these molecules are fairly simple - others are polymeric. We are just going to look at some of the simple ones. Melting and boiling points of these oxides will be much lower than those of the metal oxides or silicon dioxide. The intermolecular forces holding one molecule to its neighbors’ will be van der Waals dispersion forces or dipole-dipole interactions. The strength of these will vary depending on the size of the molecules. None of these oxides conducts electricity either as solids or as liquids. None of them contains ions or free electrons. The phosphorus oxides Phosphorus has two common oxides, phosphorus (III) oxide, P4O6, and phosphorus (V) oxide, P4O10. Phosphorus (III) oxide (tetraphosphorus hexoxide) Phosphorus (III) oxide is a white solid, melting at 24°C and boiling at 173°C. The phosphorus is using only three of its outer electrons (the 3 unpaired p electrons) to form bonds with the oxygens. Phosphorus (V) oxide (tetraphosphorus decoxide) Phosphorus (V) oxide is also a white solid, subliming (turning straight
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