CBSE Class 10 Science 2017 · Paper 31/2/1 · Question 7

Oxidising agents: alkaline potassium permanganate (${\text{KMnO}}_4$) and acidified potassium dichromate (${\text{K}}_2{\text{Cr}}_2{\text{O}}_7$), used with heating. (i) Litmus test: ethanoic acid turns blue litmus red, as it is acidic; ethanol does not change the colour of litmus, as it is neutral. (ii) Reaction with sodium hydrogencarbonate: ethanoic acid reacts with brisk effervescence, giving off carbon dioxide, which turns lime water milky (${\text{CH}}_3\text{COOH}+{\text{NaHCO}}_3\to {\text{CH}}_3\text{COONa}+{\text{H}}_2\text{O}+{\text{CO}}_2$); ethanol does not react, so there is no effervescence.