CAIE A Level Chemistry 9701 · The Periodic Table: chemical periodicity
Sodium oxide, , reacts with water to form a solution. Sulfur dioxide, , also reacts with water.
Describe the reactions of these two oxides with water, including the equations, and compare the pH of the two solutions formed. Explain the difference in pH in terms of the bonding and the oxidation number of the element combined with oxygen.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
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