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8 Cards in this Set
- Front
- Back
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The melting points vary because:
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The oxides have different bondings and structures.
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A graph of the melting points:
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The ionic lattices are:
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• Na2O
• MgO • Al2O3 |
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The ionic oxides have high melting points because:
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They have strong electrostatic forces of attraction between the oppositely charged ions.
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Mg has a higher melting point than Na because:
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Mg has a greater charge (+2) therefore it has a greater attraction with the –2 of the Oxygen.
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Al2O3 has a lower melting point than expected:
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The +3 charge on the Al polarises the anion creating a partial covalent bond which has a lower melting point than if it was purely ionic.
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SiO2 has the highest melting point of the non-metals because:
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It has a macromolecular structure which is made up of strong covalent bonds.
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P4O10 & SO2 have the weakest melting points because:
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They have simple molecular structures which are attracted weakly by intermolecular forces. (VDW & D-D)
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