Question

Primary, secondary and tertiary alcohols are distinguished by:
A. Oxidation method
B. Lucas test
C. Victor Meyer's method
D. All of the above

Answer 1

Alcohols are those organic compounds which are characterized by the presence of one, two or more hydroxyl groups (−OH) that are attached to the carbon atom in an alkyl group or hydrocarbon chain. Chemical tests are the basis of distinguishing different groups and all the above mentioned tests are chemical tests. And if the reaction takes place they show color.

Complete answer:
From your chemistry lessons you have read that alcohols are considered to be the derivatives of water where one among the hydrogen atoms is replaced by an alkyl group which is typically represented by the letter R in an organic structure. Alcohol also comes in different structures and forms.
Let us check one by one about the chemical tests that are given above to check whether they distinguish them or not,
(A). Oxidation method
Primary alcohols:- On oxidation of primary alcohols with suitable oxidizing agent like sodium dichromate $\left( N{{a}_{2}}C{{r}_{2}}{{O}_{7}} \right)$ it produces aldehydes Which on further oxidation can convert into carboxylic acid.
Secondary alcohol:- On oxidation of secondary alcohol they produce ketones and they do not have a tendency to oxidize further.
Tertiary alcohol:- it do not undergo oxidation when treated with sodium dichromate $\left( N{{a}_{2}}C{{r}_{2}}{{O}_{7}} \right)$.
So, all the three alcohols are distinguished through this way.
(B). Lucas Test:-
This chemical test distinguishes the alcohols on the basis of turbidity of the solution.
Primary alcohol:- When primary alcohol is treated with Lucas reagent that is equimolar $ZnC{{l}_{2}}$ and concentrated HCl shows no turbidity.
Secondary alcohol:- It shows turbidity in the solution just in 5 min after adding Lucas reagent.
Tertiary alcohol:- Tertiary alcohol shows instance turbidity after the addition of Lucas reagent.
So, all the three alcohols can be distinguished via this way also.
(C). Victor Mayer's Test: In this test the alcohols initially get converted into iodide when concentrated HI or red phosphorus is added into them. After that the iodides are reacted with silver nitrate solution and they form nitroalkane, and finally the formed nitroalkane is treated with $NaN{{O}_{2}}+{{H}_{2}}S{{O}_{4}}$ (nitrous acid) and they produces different colors which helps to distinguish the alcohols
Primary alcohol shows red blood colored
Secondary alcohol shows blue color
And in case of tertiary alcohol no color is observed.
So all the given chemical tests can distinguish the primary, secondary and tertiary alcohol.

Thus the correct option will be (D).

Note:
Classify on the basis of hydroxyl groups, color or colorless and also the behavior in the presence of room temperature. In the addition of ethanol the carboxylic acid that is formed from primary alcohol can be detected because it exhibits some fruity smell and through the iodoform test the ketone formed from secondary alcohol can be detected.