Question

Question #c5a85

Answer 1

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!).