Question

Which of the following alcohols would be oxidised to propan-2-one?
A.2- methylpropan-2-ol
B.Ethanol
C.Propan-2-ol
D.Butan-1-ol

Answer 1

Hint: Primary alcohols on oxidation give aldehydes (necessary condition is presence of oxidizing agent such as Collins’s Reagent or Jones’s reagent). However, oxidation of secondary alcohol gives ketones as the final product whereas in case of tertiary alcohols the product varies depending upon the oxidizing agent used.

Complete step by step solution: We will first talk about what oxidation is. So oxidation happens when there is a loss of electrons or we can say there is an increase in the oxidation state of some atom or molecule.
Talking about the propan-2-ol would be oxidised to propan-2-one. Further talking about the above each option we would say that the first option which is 2-methylpropan-2-ol is itself a tertiary alcohol and as we know that tertiary alcohols need special conditions in order to get oxidised. So its quick and easy oxidation is not possible. Further talking about its product we can say that when under wanted conditions when its oxidation will be carried out then it will form the product which will definitely have less number of atoms than the present atoms in it. So this confirms that it will first not form to propan-2-one. Now talking about option number two which is ethanol when oxidation will take place with ethanol then the product formed will be ethanol this is so because simple alcohol on oxidation gives an aldehyde. When we consider the third option then it will for sure form propan-2-one because it is a secondary alcohol which will give a ketone on oxidation. Then lastly talking about the fourth and the last option we will conclude that butan-1-ol will lead to the formation of Butanal which is again an aldehyde. 

Thus, option C is the correct answer to the given question.

Note: Oxidizing agents used are: Collin’s Reagent (\[Cr{O_3}\] or \[{C_5}{H_5}N:\] along with \[C{H_2}C{l_2}\]) or Jones reagent (\[{H_2}Cr{O_4}\]). Other reagents that can be used are hot potassium permanganate (\[HotKMn{O_4}\]) or potassium dichromate (\[{K_2}C{r_2}{O_7}\]).