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Sodium oxide, aluminium oxide and sulphur trioxide are each tested with water, with dilute acid and…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Sodium oxide, aluminium oxide and sulphur trioxide are each tested with water, with dilute acid and with dilute alkali. Say what kind of oxide each one is, and write an equation for sodium oxide and for sulphur trioxide with water. Explain the change across the period.
Need a reminder? The key ideaShow
Electronegativity is the pull of an atom in a compound on a shared pair of electrons; fluorine is 4.0 on the Pauling scale. It rises across a period and falls down a group. Valence is the number of outer electrons, or eight minus it. Oxides are basic on the left of a period, amphoteric in the middle and acidic on the right.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Sodium oxide. Basic: , an alkali.
Step 2. Aluminium oxide. Amphoteric: it does not dissolve in water, but it reacts with both acids and alkalis.
Step 3. Sulphur trioxide. Acidic: .
Step 4. The change. Across the period the elements become less metallic and more electronegative. Their oxides change from ionic and basic to covalent and acidic.
Answer: basic, amphoteric and acidic, in that order.
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