Лако-красочные материалы — производство

A good average sample of 3 to 5 grams of the paste is weighed out between two watch glasses and treated with exactly 5 grams of Mohr salt. The mixture is rinsed into a 200-cc. flask and heated for 30 minutes on a boiling water bath, after which 25 cc. concentrated hydrochloric acid is added. The mixture is heated to boiling and, after cooling, the excess of Mohr salt is back-titrated with potassium permanganate.