Question #c5a85

1 Answer
Dec 7, 2017

Ethanol can be oxidised to form acetic acid.

Explanation:

You can do this on the lab scale by warming ethanol with sodium dichromate (oxidising agent) and a small addition of concentrated sulphuric acid as catalyst. This initially forms acetaldehyde, which on further oxidation forms acetic acid.

#CH_3-CH_2-OH + Na_2Cr_2O_7 -> CH3-CHO#

#CH3-CHO + Na_2Cr_2O_7 -> CH3-COOH#

Ethanol and acetic acid can be differentiated in various ways. Physically they have different boiling points (acetic acid around 118 celcius, ethanol around 78 celcius), and different densities (1.049 #g.cm^-3# for acetic acid, 0.79 #g.cm-3# for ethanol). And chemically a key difference is acidity - pKa for ethanol in water is 15.9, whilst for acetic acid it is only 4.7.

Please note that there is no such thing as "ethanol acid" - there is "ethanoic acid" which is the IUPAC systematic name for acetic acid (although it is never used outside of school chemistry lessons!).