Question detail

Case 10 formula-choice. A student starts a worked solution. Which first step is most appropriate? Focus on that concentration solution can measured mol/dm3 in Concentrations in mol/dm3 and titration calculations, not on a neighbouring Unit 4.3 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

Using concentrations of solutions in mol/dm3 (chemistry only) (HT only)

Question

A. Case 10 formula-choice: Use the named relationship before substituting numbers for that concentration solution can measured mol/dm3
B. Case 10 formula-choice: Start with a memorised answer and add a unit later (Concentrations in mol/dm3 and titration calculations)
C. Case 10 formula-choice: Change every number into a percentage before choosing a formula (that concentration solution can measured mol/dm3)
D. Case 10 formula-choice: Use a nearby formula from a different quantitative chemistry subtopic (Using concentrations of solutions in mol/dm3 (chemistry only) (HT only))

Answer

The correct option is Case 10 formula-choice: Use the named relationship before substituting numbers for that concentration solution can measured mol/dm3.

Explanation

The correct option is Case 10 formula-choice: Use the named relationship before substituting numbers for that concentration solution can measured mol/dm3. It supports the approved learning objective by keeping the method tied to that concentration solution can measured mol/dm3 in Concentrations in mol/dm3 and titration calculations. The other options are incorrect because they either use the wrong quantitative relationship, lose the required unit, confuse coefficients with subscripts, or report an answer without a complete worked method.

Common mistake

Misunderstanding Concentration Units

Students often confuse mol/dm3 with g/dm3 when stating the concentration of a solution.

Remember that mol/dm3 measures the amount of substance in moles per cubic decimeter, while g/dm3 measures mass in grams per cubic decimeter. Focus on the definition of concentration in terms of moles. Keep the correction anchored to Concentrations in mol/dm3 and titration calculations; check formula, substitution, calculation, final answer, and unit where relevant.

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For Concentrations in mol/dm3 and titration calculations, which answer check answer best supports this Unit 4.3 objective: (chemistry only) (HT only) State that concentration of a solution can be measured in mol/dm3?