Question

Distinguish between n propyl alcohol and tert butyl alcohol

Answer 1

The carbon atom to which the alcoholic functional group is attached is a 1oCarbon atom or a Primary Carbon atom, i.e. it is linked to a single carbon atom only.

While,

this is 2-methyl propan-2-ol i.e. tertiary butyl alcohol

The carbon atom to which the alcoholic functional group is attached is a 3oCarbon atom or a Tertiary Carbon atom, i.e. it is linked to three carbon atoms.

Now this is how we can distinguish them on their structure, but if it was a CHEMICAL DISTINGUISHING TEST you’re seeking, then we can actually use Luka’s Test to distinguish between them.

Now coming to what is Luca’s Test,

Luca’s test includes a reaction between an alcohol with a Halogen hydride and it’s Zinc salt.

Now the reason we can use this for our benefit is that,

1oCarbon atoms or Primary carbon atoms undergo the reaction very fast and white fumes of Haloalkanes appear inside the flask or test tube.

2oCarbon atoms or Secondary carbon atoms undergo the reaction at a slow rate and the fumes appear after a brief interval of time.

While 3oCarbon atom or a Tertiary Carbon atom won’t undergo the reaction until and unless the reaction mixture is heated.

So, Propan-1-ol and 2-methyl propan-2-ol can be distinguished using Luca’s test as Propan-1-ol would give white fumes very easily while 2-methyl propan-2-ol won’t form any fumes until the reaction mixture is heated.