Question detail

Chemical changes case 092 redox-boundary. A student explains a redox change. Which option uses the safest chemistry wording? Focus on changes when strong and weak acids are diluted in Strong and weak acids (HT only), 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 092 redox-boundary: Links oxidation or reduction to the correct electron or oxygen change for changes when strong and weak acids are diluted
B. Chemical changes case 092 redox-boundary: Uses reduction and displacement as if they mean the same thing (Strong and weak acids (HT only))
C. Chemical changes case 092 redox-boundary: Calls the reaction redox without naming what changes (changes when strong and weak acids are diluted)
D. Chemical changes case 092 redox-boundary: Confuses oxidation state with ionic charge in the answer (Reactions of acids)

Answer

The correct option is Chemical changes case 092 redox-boundary: Links oxidation or reduction to the correct electron or oxygen change for changes when strong and weak acids are diluted.

Explanation

The correct option is Chemical changes case 092 redox-boundary: Links oxidation or reduction to the correct electron or oxygen change for changes when strong and weak acids are diluted. It is correct because it directly supports the approved learning objective to (HT only) Compare pH changes when strong and weak acids are diluted in Strong and weak acids (HT only). 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

Misunderstanding pH Changes

Students often believe that diluting a strong acid will change its pH more significantly than diluting a weak acid.

Emphasize that while both strong and weak acids will have their pH increase upon dilution, the strong acid will still remain at a lower pH compared to the weak acid after dilution.

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For Strong and weak acids (HT only), which electrolysis focus answer best supports this Unit 4.4 objective: (HT only) Compare pH changes when strong and weak acids are diluted?