Sulfamic acid. Physical and chemical properties. Application
Sulfamic acid (other names: aminosulfonic acid, amidosulfuric acid, sulfuric acid monoamide) is a substance that is colorless crystals of rhombic form. The formula for this compound is: NH2SO2OH (or NH2SO3H).
Physical properties of aminosulfonic acid:
1. This substance exists in the form of colorless crystals, which have the shape of a diamond. The zonation is orthorhombic: b = 0.8025 nm, a = 0.8037 nm, z = 8, c = 0.9237 nm. In the form of a zwitterion, it exists in a crystalline state.
2. Sulfamic acid has the following molecular weight: 97,098 amu. The melting point is 205 degrees, the decomposition is 260 degrees Celsius.
3. The solubility in acetone at 25 degrees is 0.04; in water at 20 degrees 17,57, at 40 degrees 22,77 and at 80 degrees - 32,01; in diethyl alcohol at 25 ° C, 0.01; in formamide at 25 degrees 0.18; in methanol at 25 degrees 0.4.
4. It has a density of 2.126 grams per centimeter³.
Chemical properties of sulfamic acid:
1. When heated to 260 degrees, it decomposes into SO2 (sulfur oxide ll), SO3 (sulfur oxide lll), N2 (nitrogen) and H2O (water). This is what this reaction looks like:
NH2SO2OH = SO2 (oxides oxide ll) + SO3 (sulfur oxide lll) + N2 (nitrogen, released as gas) + H2O (water).
2. At room temperature, this substance is practically not subjected to hydrolysis. But at too high temperatures it is hydrolyzed to NH4HSO4. And in the acidic environment the reaction rate is significantly increased.
3. With various metals, their carbonates, hydroxides and oxides, aminosulfonic acid forms NH2SO3M salts (collectively called sulfamates), with thionyl chloride SOCl2-NH2SO2Cl sulfamoyl chloride.
4. When interacting with HNO2 (nitrous acid), it is deaminated with the oxidizing - NH2SO3H + HNO2H2O + N2 (nitrogen, released as a gas) + H2SO4 (sulfuric acid). This reaction is used to determine the amount of sulfuric acid monoamide and for the decomposition of excess nitric acid (HNO2) in the production of azo dyes.
5. Sulfamic acid is oxidized by chlorine (Cl), bromine (Br), potassium permanganate (KMnO4) and chlorates to sulfuric acid (H2SO4) and nitrogen (N2).
6. The reaction of this acid with HClO (hypochlorous acid) or NaClO (sodium hypochlorite) results in the formation of N, N-dichloro- or N-chloro derivatives. Reaction with sodium (Na) in liquid ammonia (NH3) to NaSO3NHNa, with sodium sulfate (Na2SO4) to 6HSO3NH2 · 5Na2SO4 · 15H2O.
7. Also sulfuric acid monoamide reacts with primary alcohols and secondary, with phenols. Tertiary, secondary and primary amines form with this acid aminosulfamates, and amides of carboxylic-ammonium acids N-acyl sulfamates.
8. For the identification of aminosulfonic acid, a reaction with nitrous acid (HNO2) or fusion with benzoin (C14H12O3) is used.
Application of sulfuric acid monoamide
1. Industrial chemistry: for cleaning equipment from beer and milk stone, from various mineral deposits (oxide films, hardness salts, iron compounds). The production of hydrochloric acid in this case becomes unprofitable, since sulfamic acid is less corrosive.
2. In everyday life and at public catering enterprises: for the processing of kitchen and dining utensils, as part of certain detergents.
3. As a raw material for the preparation of certain chemical compounds, for example, herbicides and fireproof materials.
4. In electroplating: for etching food and for the creation of electrolytes.
5. To remove mucus from swimming pools (their water-cooling systems).
6. When cleaning machines designed to create paper.
7. When processing the oil well zone.
How should sulfamic acid be stored properly, and what precautions should be taken when using it?
Monoamide of sulfuric acid is classified as a flame-retardant substance. By the degree of exposure to a living organism, it refers to compounds of the third hazard class. Causes severe burns to the skin and mucous membranes.
Store this acid in double polyethylenebags (capacity forty kilograms), designed specifically for chemical products. It is worth considering that the product is readily soluble in H2O (water). With prolonged storage is caked.
