CAIE A Level Chemistry 9701 · Equilibria
Four 0.10 mol dm aqueous solutions are prepared: hydrochloric acid (), ethanoic acid (), sodium hydroxide (), and ammonia (). A student measures the pH of each solution using a pH meter and also tests the electrical conductivity and the rate of reaction with magnesium ribbon.
Describe, using the Brønsted–Lowry theory of acids and bases, how and why these four solutions differ in their pH values, electrical conductivity, and reaction with magnesium ribbon.
7 marks, so the mark scheme is looking for about 7 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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