(5) A 0.5-g. p-aminophenol sample was dissolved in 600 ml. of distilled water containing 10 g. of potassium bromide and 25 ml. of concentrated hydrochloric acid. Tenth-normal sodium nitrite was added in 5-ml. portions until indication of an excess (starch-iodide paper), persistent for 15 minutes, was obtained. The solution was then back titrated with 0.1 N sulfanilic acid and finally adjusted with more of the 0.1. V sodium nitrite. A faint positive ...
