In this experiment, sodium carbonate and ammonium chloride were produced simultaneously from salt, ammonia and carbon dioxide, which are by-products of synthetic ammonia industry. The total reaction equation is "combined alkali production method", also known as "Hou's alkali production method".
In the production of combined soda in China, the combined soda production process of one carbonization, two ammonia absorption, one salt addition and ice machine cooling is generally adopted. Extended data of alkali classification. According to the number of hydroxyl ions ionized by an alkali molecule, it can be divided into monobasic binary basic polybasic bases. According to solubility: soluble alkali, slightly soluble alkali and insoluble alkali. According to ionization ability: strong base and weak base. According to use: industrial alkali, edible alkali, industrial alkali: industrial soda ash (sodium carbonate), industrial caustic soda (sodium hydroxide NaOH), industrial heavy substance (NaHCO3).
The purity and impurity content of industrial alkali can meet the general industrial use, and the process is relatively simple, which can be used in large-scale industrial production and is harmful to human body. Edible alkali: edible soda ash (sodium carbonate Na2CO3, with the same molecular formula, but without industrial soda ash impurities) and edible baking soda (sodium bicarbonate NaHCO3). Simply put, the solubility of ammonia gas is higher than that of carbon dioxide, and ammonia gas is easily dissolved in water to form ammonia water, while the reaction between ammonia water and carbon dioxide is equivalent to acid-base neutralization, which is easier to carry out, while the amount of carbon dioxide dissolved in water to form carbonic acid is not only small but also unstable, and the amount of ammonium carbonate generated is greatly reduced, so ammonia gas is introduced first and then carbon dioxide is introduced.