A-A-52092 Ammonium Chloride, TechnicalThis commercial item description covers technical ammonium chloride in brick form for use in cleaning soldering irons and in white crystal form for use in batteries and for galvanizing purposes.

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A-A-52092A

3. SALIENT CHARACTERISTICS. The ammonium chloride shall conform to the chemical and physical characteristics of table II when tested as specified therein.

TABLE II. Physical and chemical requirements.

Requirements	Minimum or criteria	Maximum or criteria	Test method
Volatile matter, %	-----	1.0	see 3.1
Ammonium chloride content, %	99.0	-----	see 3.2
Residue on ignition (dry basis), %	-----	0.8	see 3.3
Free acid	Pass test	-----	see 3.4
Heavy metals	Pass test	-----	see 3.5
Sieve particle size graduation, %	90.0	-----	see 3.6

3.1 Volatile matter test method. Place approximately 6 grams of the material, weighed to the nearest 0.1 milligram, into a flat-bottomed, tared dish, 2 to 3 inches in diameter, spreading the material over the bottom. Dry over sulfuric acid at room temperature (approximately 25oC) for 4 hours. Weigh to the nearest 0.1 milligram and calculate the percent loss as volatile matter as follows:

Percent volatile matter = 100 (W-R) W

Where: W = weight of specimen used, in grams

R = weight of residue after drying, in grams

3.2 Ammonium chloride content test method. Dissolve approximately 0.2 grams of the dried specimen (see volatile matter), weighted to the nearest 0.1 milligram, in approximately 40 milliliters of water. Add exactly 50 milliliters of 0.1 N silver nitrate solution and 5 milliliters of concentrated nitric acid. Make up the mixture to exactly 100 milliliters with water. Filter through a dry filter and reject the first 10 milliliters of the filtrate. Take exactly 50 milliliters of the filtrate and add 2 milliliters of an 8 percent solution of the ferric ammonium sulfate. Titrate the excess of silver nitrate with 0.1 N ammonium thiocyanate and calculate the percent ammonium chloride as follows:

Percent ammonium chloride = 10.70 (25N - VM) W

Where: N = normality of silver nitrate solution

V = volume of ammonium thiocyanate solution used, in milliliters

M = normality of ammonium thiocynate solution

W = weight of specimen used, in grams

3.3 Residue on ignition (dry basis) test method. Weigh to the nearest 0.1 milligrams approximately 5 grams of the dried specimen (see volatile matter) into a tared crucible. Add