CAIE A Level Chemistry 9701 · Carboxylic acids and derivatives
The pH of a 0.1 mol dm aqueous solution of chloroethanoic acid, , is lower than the pH of a 0.1 mol dm aqueous solution of ethanoic acid, . Explain this observation in terms of the inductive effect and the stability of the conjugate base.
6 marks, so the mark scheme is looking for about 6 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
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