Experimental preparation of ammonia: in the laboratory, ammonia is usually prepared by the reaction of ammonium salt with alkali, or by the easy hydrolysis of nitride;
The rapid preparation method of ammonia in laboratory is to prepare ammonia with concentrated ammonia and solid NaOH.
Extended data:
Harmful properties of inhaled ammonia:
The irritation of ammonia is a reliable alarm signal of harmful concentration. However, due to olfactory fatigue, it is difficult to detect low concentration of ammonia after long-term contact. Inhalation is the main route of contact, and the poisoning manifestations after inhaling ammonia mainly include the following aspects.
Mild ammonia inhalation poisoning is characterized by rhinitis, pharyngitis, sore throat and hoarseness. Ammonia entering trachea and bronchus can cause cough, expectoration and blood in sputum. In severe cases, hemoptysis with pulmonary edema, dyspnea, white or bloody foam sputum, and large and medium-sized blisters on both lungs may occur. The patient has burning throat, cough, expectoration or hemoptysis, chest tightness and retrosternal pain.
The occurrence of acute ammonia inhalation poisoning is mostly caused by accidents such as pipeline rupture and valve burst. Acute ammonia poisoning is mainly manifested as irritation and burns of respiratory mucosa. Its symptoms vary with ammonia concentration, inhalation time and personal sensitivity.
1. Acute mild poisoning: dry throat, sore throat, hoarseness, cough, expectoration, chest tightness and mild headache, dizziness, fatigue, bronchitis and bronchiolitis.
2. Acute and moderate poisoning: the above symptoms are aggravated, breathing is difficult, sometimes there are bloodshot sputum, mild cyanosis, obvious conjunctival congestion, laryngeal edema, and dry and wet snoring in the lungs.
3, acute severe poisoning: severe cough, coughing up a lot of pink foam-like sputum, shortness of breath, palpitation, dyspnea, laryngeal edema further aggravated, cyanosis, or acute respiratory distress syndrome, severe pneumothorax and mediastinal emphysema.
4. Severe inhalation poisoning: Laryngeal edema, glottic stenosis and respiratory mucosa shedding may occur, which may cause tracheal obstruction and suffocation. Inhalation of high concentration ammonia can directly affect the permeability of pulmonary capillaries, cause pulmonary edema, and induce convulsions, convulsions, drowsiness, coma and other conscious disorders. Individual patients who inhale extremely concentrated ammonia will have respiratory and cardiac arrest.
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