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How do you distinguish between primary and secondary alcohols by chemical reaction?

How do you distinguish between primary and secondary alcohols by chemical reaction?
Original post by Nolan2
How do you distinguish between primary and secondary alcohols by chemical reaction?
warm and distill with an oxidising agent e.g. acidified potassium dichromate - forming a aldehyde (if primary) or ketone (if secondary) then using Tollens reagent for example which is the test for an aldehyde so if a silver mirror forms then an aldehyde has been formed therefore was a primary alcohol and if not then was a secondary alcohol - hope that answers your question 🙂
Original post by Nolan2
How do you distinguish between primary and secondary alcohols by chemical reaction?

You can use Lucas' reagent (zinc chloride/conc. HCl solution).
If it goes cloudy after a few minutes it is secondary alcohol
Primary alcohols do not react
Reply 3
Original post by Nolan2
How do you distinguish between primary and secondary alcohols by chemical reaction?

It depends on what spec you're doing. There are a few OCR A friendly methods, which no doubt would be fine on other specs. I'd reflux with H+/Cr2O7^2- then add 2,4-DNP to the products.
Original post by Nolan2
How do you distinguish between primary and secondary alcohols by chemical reaction?

The method universal to all A level syllabi has already been outlined by rosie3214. If asked this question in an exam, that is by far the safest response.

Alternatively, you could oxidise the alcohol under distillation and then see if the distillate turns acidified K2Cr2O7 green.
(edited 4 weeks ago)

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