Question
Question: Which of the following alcohols can be oxidised by \({K_2}C{r_2}{O_7}\) (A) Ethanol (B) Tert But...
Which of the following alcohols can be oxidised by K2Cr2O7
(A) Ethanol
(B) Tert Butyl Alcohol
(C) Isopropyl alcohol
(D) Allyl alcohol
Solution
Potassium dichromate is a strong oxidising agent which oxidises almost all types of functional groups including alcohol. We will check according to the structure of alcohol which will be oxidised or not.
Complete Solution :
-Potassium dichromate is a strong oxidising agent which oxidises all the functional groups including alcohol.
- we have ethanol given it converts into ethanoic acid
- reaction is as follows
- CH3CH2OH→CH3COOH in presence of potassium permanganate
-we have tertiary butyl alcohol , the reaction is as follows
-(CH3)3C−OH→× it does not give reaction as tertiary butyl alcohol can’t be oxidised
so this option is incorrect
-next we have isopropyl alcohol it also gets oxidised in presence of potassium dichromate
-the reaction is as follows
CH3−CHOH−CH3→CH3COCH3 here it oxidises into acetone.
-Further we have allyl alcohol which converts into acid
The reaction is as follows
-CH2=CH−CH2−OH→CH2=CH−CH2−COOH
-It gets converted to acid in presence of potassium dichromate
So, the correct answer is “Option A,C and D”.
Note: Acidified potassium dichromate is used to change to green when alcohol is oxidised and is used as a test for alcohols .