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Which reagent gives the same visible result with propanal and with propan-2-ol? A 2,4-dinitrophenylhydrazine reagent B acidified potassium dichromate(VI) C sodium D Tollens' reagent - CIE - A-Level Chemistry - Question 20 - 2011 - Paper 1
Question 20
Which reagent gives the same visible result with propanal and with propan-2-ol? A 2,4-dinitrophenylhydrazine reagent B acidified potassium dichromate(VI) C sodium... show full transcript
Worked Solution & Example Answer:Which reagent gives the same visible result with propanal and with propan-2-ol? A 2,4-dinitrophenylhydrazine reagent B acidified potassium dichromate(VI) C sodium D Tollens' reagent - CIE - A-Level Chemistry - Question 20 - 2011 - Paper 1
Step 1
B acidified potassium dichromate(VI)
Answer
To determine which reagent gives the same visible result with both propanal and propan-2-ol, we analyze the reaction of each reagent with these two compounds:
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Propanal: As an aldehyde, propanal will react with acidified potassium dichromate(VI) resulting in oxidation to a carboxylic acid, creating a visible change in color.
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Propan-2-ol: This compound, being a secondary alcohol, will also be oxidized by acidified potassium dichromate(VI) to form a ketone, which does not typically undergo further oxidation under these conditions, resulting in a visible color change as well.
Since both propanal and propan-2-ol react similarly with acidified potassium dichromate(VI) and undergo oxidation leading to a visible result, the correct answer is B.