ALCOHOLS
REACTIONS OF ALIPHATIC ALCOHOLS with sodium.
Treat 2 ml. of absolute methyl alcohol with a small thin slice of dry, freshly-cut sodium Observe the result. Cool the solution when all the sodium has reacted. Add a little water and test the solution with litmus paper. Obtain five small dry test-tubes and introduce 1 ml. of the following alcohols into each : ethyl alcohol, n-butyl alcohol, sec.-butyl alcohol, q/c/ohexanol and tert.-butyl alcohol. Add a minute fragment of sodium to each and observe the rate of reaction. Arrange the alcohols in the order of decreasing reactivity towards sodium. The reaction with sodium is by no means an infallible practical test for alcohols since, strictly speaking, it is applicable only to pure anhydrous liquids. Traces of water, present as impurities, would give an initial evolution of hydrogen, but reaction would stop after a time if an alcohol is absent: furthermore, certain esters and ketones also evolve hydrogen when treated with sodium. It may, however, be assumed that if no hydrogen is evolved in the test, the substance is not an alcohol.
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