7205. Phenacetolin

Nomenclature

CAS number: 1340-26-7
Degener's indicator.

Description and references

Reaction product of concd H2SO4 and glacial acetic acid on phenol.

Properties

Yellowish-brown powder. Slightly sol in water; sol in alc.

Use

Has been employed as indicator, particularly for mixtures of alkali hydroxides and carbonates; the yellow color changes to red when hydroxide is neutralized, and again to yellow when carbonate is fully dec by acid; was also used for determining alkalinity of water. The indicator soln is prepd by digesting 1 g with 100 ml warm alcohol and filtering after cooling; 2-3 drops used for 100 ml liquid.