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Which would be the best reagent to determine whether an unknown substance was 2-methylpropan-1-ol or 2-methylpropan-2-ol? A - HSC - SSCE Chemistry - Question 5 - 2024 - Paper 1
Question 5
Which would be the best reagent to determine whether an unknown substance was 2-methylpropan-1-ol or 2-methylpropan-2-ol? A. Bromine water B. Potassium nitrate solut... show full transcript
Worked Solution & Example Answer:Which would be the best reagent to determine whether an unknown substance was 2-methylpropan-1-ol or 2-methylpropan-2-ol? A - HSC - SSCE Chemistry - Question 5 - 2024 - Paper 1
Step 1
Select the best reagent
Answer
To determine whether the unknown substance is 2-methylpropan-1-ol or 2-methylpropan-2-ol, it is essential to identify if the alcohol is a primary or secondary alcohol. Among the given reagents, acidified potassium permanganate solution (D) is the best choice. The reason is that:
- Acidified potassium permanganate is a strong oxidizing agent.
- 2-methylpropan-1-ol (a primary alcohol) will undergo oxidation to form an aldehyde.
- 2-methylpropan-2-ol (a secondary alcohol) will be oxidized to a ketone.
Observations can be made based on the change in color of the reagent; if the purple color of potassium permanganate disappears, it indicates a positive reaction, thus confirming the presence of a primary alcohol.