Question detail

Chemical changes case 033 reactivity-evidence. A student uses the reactivity series to justify an observation. Which option is best? Focus on how obtain pure dry sample named soluble salt in Soluble salts, not on a neighbouring Unit 4.4 reaction idea.

Try the question, check the answer, then read the explanation to understand the curriculum point.

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At a glance

MCQ

Type

practice

Style

Topic

Reactions of acids

Question

A. Chemical changes case 033 reactivity-evidence: Uses the relative reactivity order to predict the change for how obtain pure dry sample named soluble salt
B. Chemical changes case 033 reactivity-evidence: Chooses the product by memorising a colour instead of the series (Soluble salts)
C. Chemical changes case 033 reactivity-evidence: Says any metal can displace any other metal ion (how obtain pure dry sample named soluble salt)
D. Chemical changes case 033 reactivity-evidence: Ignores whether the reacting substance is more or less reactive (Reactions of acids)

Answer

The correct option is Chemical changes case 033 reactivity-evidence: Uses the relative reactivity order to predict the change for how obtain pure dry sample named soluble salt.

Explanation

The correct option is Chemical changes case 033 reactivity-evidence: Uses the relative reactivity order to predict the change for how obtain pure dry sample named soluble salt. It is correct because it directly supports the approved learning objective to explain how to obtain a pure dry sample of a named soluble salt in the required practical in Soluble salts. The other options are incorrect because they blur a Unit 4.4 concept boundary: acid versus alkali versus base, oxidation versus reduction, displacement versus reduction, electrolysis versus electroplating, anode versus cathode, positive versus negative ions, oxidation state versus ionic charge, or strong acid versus concentrated acid.

Common mistake

Common Mistake in Salt Preparation

Students often forget to add the insoluble solid in excess when preparing a soluble salt, leading to incomplete reaction and impurities in the final product.

Always add the insoluble solid in excess to ensure that all the acid reacts and to filter out any unreacted solid, resulting in a pure dry sample of the soluble salt.

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