Question

How would you bring about the following conversions? Name the process and write the reaction involved.

Answer 1

1. When ethanol is heated at 443 K with excess concentrated sulphuric acid, it gives ethene.
   \[\ce{C2H5OH \overset{CONC.H2SO4}{->} C2H4 + H2O}\]
   This process is known as dehydration because concentrated sulphuric acid is a dehydrating agent which removes water from ethanol. 
2. When propanol is treated with alkaline potassium permanganate or acidified potassium dichromate, it is converted to propanoic acid.
   \[\ce{CH3CH2CH2OH \overset{Alkaline KMnO3}{->}CH3CH2COOH}\]
3. Alkaline KMnO₄ or acidified K₂Cr₂O₇ is an oxidising agent which is adding oxygen to propanol. Hence, it is an oxidation reaction.