Ammonia, aqueous.

§ 21.96 Ammonia, aqueous. (a) Alkalinity. Strongly alkaline to litmus. (b) Ammonia content. 27 to 30 percent by weight. Accurately weigh a glass-stoppered flask containing 25 mL of water, add about 2 mL of the sample, stopper, and weigh again. Add methyl red indicator, and titrate with 1 N sulfuric acid. Each mL of 1 N sulfuric acid is equivalent to 17.03 mg of NH 3 (c) Color. Colorless liquid. (d) Non-volatile residue. 2 mg maximum. Dilute a portion of the sample with 1 1/2 times its volume of distilled water. Evaporate 10 mL of this product to dryness in a tared platinum or porcelain dish. Dry residue at 105 °C. for 1 hour, cool and weigh. (e) Odor. Characteristic (exceedingly pungent). (f) Specific gravity at 20 °/4 °C. 0.8920 to 0.9010. [T.D. ATF–133, 48 FR 24673, June 2, 1983. Redesignated by T.D. ATF–442, 66 FR 12854, Mar. 1, 2001]