Sulfamic acid

  • Amidosulfuric
  • Sulfamic
  • Sulfamic
  • Sulfamic

Colorless, odorless, non- hygroscopic, orthorhombic crystals

Fixed

2.13 g · cm -3

205 ° C ( decomposition)

0.78 Pa ( 20 ° C)

~ 1

  • Good in water ( 213 g · l-1 at 20 ° C ), ammonia, formamide and DMSO
  • In most organic solvents, sparingly soluble

Attention

> 2000 mg · kg -1 ( LD50, rat, oral)

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Sulfamic acid is a colorless crystalline substance which can be considered as the acid amide sulfuric acid. Its salts are called Amidosulfonate or Sulfamates.

Production

The preparation of sulfamic acid is carried out with urea, sulfuric acid and disulphuric:

Properties

Sulfamic acid forms colorless to whitish -yellow crystals which melt at 205 ° C under incipient decomposition and heavy smoke and dissolve well in water. The solution is acidic. Due to the acid properties it acts in direct contact irritant and corrosive to eyes and skin. Sulfamic acid is not hygroscopic and can therefore be used as a primary standard.

The structure of sulfamic acid can be described H3N - SO3 by the formula . When sulfamic acid therefore it is a zwitterion. The tautomeric form H2N - SO2 ( OH) is not present in the solid.

Use

Sulfamic acid is (usually next to phosphoric acid or citric acid) used a part of decalcifiers and sanitary cleaners, in the laboratory it is used as primary standard and for destroying nitrite:

In electroplating using sulfamic acid to adjust the pH value to pH 3.9 by Nickelsulfamatbädern to 4.2. Also, a solution of sulfamic acid with sodium lauryl sulfate at 35 to 40 ° C is used to activate a nickel layer.

Determination

The content of an aqueous sulfamic acid solution can be determined by Titrationanalyse. The reaction formula of the acid -base titration is as follows:

CAS registry number PubChem Vapor pressure Dimethyl sulfoxide Dangerous Substances Directive (67/548/EEC)
56888
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