(also acid ethylsulfate, ethyl hydrogen sulfate), C2H5OSO2OH, a syrupy, hygroscopic liquid with a density of 1.316 g/cm3 at 17°C.
Ethylsulfuric acid is readily soluble in water, alcohol, and ether. A strong monobasic acid, it forms such derivatives as salts (including C2H5OSO2ONa) and ethers of the general formula C2H5OSO2OR.
Ethylsulfuric acid is formed as an intermediate in an industrial method of producing ethyl alcohol and is usually produced by reacting ethyl alcohol with sulfuric acid. It is used mainly for ethylation—that is, the introduction of an ethyl group into chemical compounds; it is used, for example, in the production of ethyl bromide.