Sodium nitrite is an inorganic compound with the chemical formula of sodium nitrite. It is a white crystalline powder with salty taste and carcinogenicity. It is an industrial salt, which is widely used as concrete coagulant and textile treatment agent in construction, textile, printing and dyeing industries.
Sodium nitrite consists of three elements: sodium, nitrogen and oxygen. Among them, the relative atomic mass of sodium is 22.99, that of nitrogen is 14.0067, and that of oxygen is 16.00. Therefore, the mass ratio of sodium, nitrogen and oxygen in sodium nitrite is 22.99:14.0067:16.00.
Specifically, if we have 1 sodium atom, we need 1 nitrogen atom and 2 oxygen atoms. Therefore, the atomic number ratio of sodium, nitrogen and oxygen is 1: 1: 2. However, their mass ratio is not simple 1: 1: 2.
So option d is wrong. If the mass ratio of sodium, nitrogen and oxygen in sodium nitrite is 1: 1: 2 according to option D, then we can infer that the mass of 1 sodium atom is equal to the mass of 1 nitrogen atom plus the mass of 2 oxygen atoms, which is obviously incorrect.
Uses of sodium nitrite:
1. Colorants and preservatives in meat processing
In the processing of meat products, sodium nitrite is widely used as a color developer and preservative. Firstly, sodium nitrite can react with myoglobin to produce stable nitrosmyoglobin, which makes meat products appear bright red.
Secondly, sodium nitrite can inhibit the growth and reproduction of Clostridium botulinum, thus preventing meat products from spoilage. In addition, sodium nitrite can also promote the texture and taste of meat products and improve their quality and shelf life.
2. mordants and bleaches for fabric dyeing
Sodium nitrite can be used as mordant and bleaching agent for fabric dyeing. In the dyeing process, sodium nitrite can promote the penetration and diffusion of dyes and improve the dyeing effect. At the same time, sodium nitrite can also react with fabric fibers to improve the feel and appearance of the fabric. In addition, sodium nitrite can also be used as a bleaching agent to oxidize and decompose the pigments in fabric fibers, thus making the fabric white.
3, metal heat treatment agent
In the process of metal heat treatment, sodium nitrite can be used as a protective gas to prevent oxidation and corrosion of metal surface. At the same time, sodium nitrite can also promote the heating and cooling speed of metal surface and improve the hardness and wear resistance of metal.