Primary amine is flammable, and its vapour may combine with air to generate explosive combinations, with an explosion limit of 5% to 21%. (4.95 percent -20.75 percent ). Ammonia has a higher alkalinity after liquefaction of the fuming body.
NH4++OH-=NH3↑+H2O
The relevance of diazotization stems from the fact that diazotrope salts have a particularly active chemical nature and may be found in a wide range of processes. Because diazonium salts may react with phenols or aromatic amines to form azo compounds, diazonation is the primary method for making azo colors (see Dyes). Under the proper circumstances, the diazo group (-N sledge X) in diazonium salts can undergo a variety of transformations, introducing hydroxyl, halogen, cyano, mercapto, and hydrazine groups to the aromatic ring. Diazo salts can be utilized to make non-silver photographic materials in some cases. Ammonia is a colorless, odorless gas that is readily soluble in water and can exist on its own. It has the molecular formula NH3 and a triangular conical molecular structure in which the nitrogen atom has a lone pair of electrons; ammonia is a colourless, odorous gas that is readily soluble in water and can exist on its own.
Process characteristics: Diazotization is an exothermic process with a rapid reaction rate. Because the diazonium salt is unstable, diazotization is normally carried out with a substantial excess of inorganic acid and always with a minor excess of sodium nitrite to enhance the stability of the diazonium salt and avoid side reactions. Light or heat can cause diazotrope salts to decompose. In a dry condition, some diazonium salts can disintegrate fast and trigger an explosion if exposed to heat or stress. As a result, diazotization should be done at a temperature of 0-5°C. The diazotized salt solution should not be kept for an extended period of time and should not be dried. Particular diazo compounds can be produced into a stable form under certain conditions, depending on the demands of the dyeing industry (see ice dyeing dyes). Methods of diazotization: The method used is determined by the type of the aromatic primary amine being diazotized. These are the most essential approaches.
(1) Diazotization that is positive. The diazotisation of most aromatic primary amines dissolved in dilute inorganic acids is accomplished by adding aqueous sodium nitrite to the aromatic primary amine's aqueous inorganic acid solution.
(2) Diazotization in reverse. This procedure is used to diazotize aromatic amine, which is difficult to dissolve in dilute acids. The aromatic amine is first dissolved in alkali, then combined with a sodium nitrite solution, and then added to dilute inorganic acid.
(3) The technique of nitrosyl sulphate. It is used to diazotize aromatic primary amines that are difficult to dissolve in dilute acid, in which case the aromatic primary amine is first dissolved in concentrated sulphuric acid or glacial acetic acid, and then nitrosyl sulphuric acid solution is added.
In a kettle reactor, diazotization is usually done on a regular basis. Enamel or tile-lined pans are commonly used to avoid corrosion of the dilute acid, and the reaction temperature is regulated by introducing crushed ice directly into the reactor or conveying frozen brine via a jacket or enamelled snake tube.
English
日本語
한국어
français
Deutsch
русский
tiếng việt
Türkçe
ไทย
اردو
