by Barium Chloride, 0.05 M:
Dissolve 12.2 g of barium chloride in sufficient water to produce 1000 ml. Standardize the solution in the following manner.
To 10.0 ml of the solution add 60 ml of water, 3 ml of strong ammonia solution and 0.5 to 1 mg of metalphthalein as indicator and titrate with 0.05 M disodium edetate. As the solution begins to decolorise, add 50 ml of ethanol (95 percent) and titrate until the bluish violet colour is discharged. 1 ml of 0.05 M disodium edetate is equivalent to 0.012215 g of BaCl2,2H2O.
Benzethonium Chloride, 0.004 M:
Dissolve 1.792 g of benzethonium chloride, previously dried to constant weight at 105°, in sufficient water to produce 1000 ml. Standardize the solution from the content of C27H42CINO2 in the dried benzethonium chloride determined in the following manner.
Dissolve 0.35 g of the dried substance in 30 ml of anhydrous Glacial acetic acid, add 6 ml of mercuric acetate solution.
Titrate with 0.05 ml of crystal violet solution as indicator. Perform a blank determination and make any necessary correction. 1 ml of 0.1 M perchloric acid is equivalent to 0.04481 g of C27H42CINO2.
