Question

Differentiate between primary, secondary and tertiary alcohol By Victor Meyer test.

Answer 1

Victor Meyer test: The Victor Meyer test is used to differentiate between primary, secondary and tertiary alcohol by the colour they obtain when they interact with the victor Meyer reagent.

Steps to carry out test:

• The alcohol is treated with Iodine ($\mathrm{I}$) in the presence of Red Phosphorus ($\mathrm{P}$)to give Iodo-alkane.
• Iodoalkane is allowed to react with alcoholic silver nitrite (${\mathrm{AgNO}}_2$) to obtain nitro alkane.
• The nitro alkane is then treated with nitrous acid ${\mathrm{HNO}}_2$ and the solution which resulted is made alkaline.
• The colour is observed as below.

The conclusion drawn from the test:

Primary Alcohol	Secondary Alcohol	Tertiary alcohol
When the above alkaline prepared solution is reacted with primary alcohol, a blood-red solution is formed.	When the above alkaline prepared solution is reacted with secondary alcohol, the blue coloured solution is formed.	When the above alkaline prepared solution is reacted with tertiary alcohol, no positive test is observed and no coloured solution is formed.

Therefore, by using the Victor Meyer test, we can differentiate three types of alcohol.