Question detail
A student is testing chromatography. Which choice keeps the observation and conclusion correctly linked?
Try the question, check the answer, then read the explanation to understand the curriculum point.
At a glance
MCQ
Type
practice
Style
Topic
Purity, formulations and chromatography
Question
- A. The sample is pure
- B. The sample is impure
- C. The sample is a single element
- D. The sample has no components
Answer
The correct answer is The sample is impure. It matches chromatography because the evidence is spot and solvent-front distances and the expected result is Rf or separation evidence.
Explanation
The correct option is The sample is impure. The important distinction is that chromatography must be identified from spot and solvent-front distances; answers that swap in a different test or result do not match Chromatography. Other options are weaker when they confuse gas tests, flame colours, ion-test precipitates, chromatography evidence, or pure-substance/formulation wording.
Common mistake
Understanding Rf Values
Students often think Rf values can be compared across different experiments without considering the conditions.
Emphasize that Rf values are only meaningful when the chromatography is performed under the same conditions, such as temperature and solvent.
Related flashcards
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Related practice questions
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