How will you distinguish among the following pairs?
(a) n-Propyl alcohol and isopropyl alcohol
(b) n-Butyl, sec-butyl and tert-butyl alcohols.
(c ) Ethanol and chloroform.
(d) Ethanol and acetone.
(e ) Ethanol and propan-1-ol.
(f) Glycerol and suger solution.
(g) Allyl alcohol and n-propyl alcohol.

Answer

(a) n-Propyl alcohol does not give iodoform test while isopropyl alcohol forms yellow crystalline iodoform when treated with `I_(2)` and NaOH.
(b) Perform Lucas test. Tert-Butyl alcohol reacts immediately with `(ZnCl_(2)+HCl)` Lucas reagent reagent to form cloudiness, secondary butly alcohol reacts within 5 minutes while n-butyl alcohol does not react at all at room temperature.
(c ) Chloroform gives isocyanide test. This test is not given by ethanol. Ethanol gives iodoform test. This test is not given by chloroform .
(d) Ethanol undergoes oxidation with dilute acidified `K_(2)Cr_(2)O_(7)` and gives pungent odour due to formation of acetaldehyde . Acetone gives a red colour with sodium nitroprusside in the presence of NaOH .
(e ) Ethyl alcohol ( ethanol) gives iodoform test. This test is not given by propane-1-ol.
(f) Glycerol on heating with `KHSO_(4)` forms a pungent odour compound, acrolein. This test is not given by sugar solution. The pink colour of borax and phenolphthalein disappears when glycerol is added to it in cold bu reappears on heating , however, it again disappears on cooling . This test is not given by sugar solution.
(g) Allyl alcohol reacts immediately with Lucas reagent and gives white turbidity is less than one minute while n-propyl alcohol does not react .