How to distinguish between industrial salt and edible salt, medical salt and edible salt

How to distinguish industrial salt from edible salt

Edible salt contains not only iodine, but also undergoes rigorous inspection before leaving the factory. All indicators meet the national edible salt standard. From the appearance, it is white, fine sand-like, and has very little water. There will be no condensation when kneaded by hand. sense. Industrial salt does not contain iodine, the color is gray, and the shape is mostly granular, with large moisture content. The shape of industrial well mineral salt is similar to edible salt, but it contains toxic substances and does not contain iodine.

1. Structurally: table salt is relatively pure sodium chloride, the chemical formula of sodium chloride is NaCl, the formula weight is 58.44, and it is composed of chloride ion and sodium ion. In addition to sodium chloride, industrial salt also contains sodium nitrite that exceeds the standard. Its chemical formula is NaNO2 and the formula weight is 69.00. It consists of nitrite ions and sodium ions.

2. Nature: The salt is relatively stable, and the aqueous solution is neutral. Sodium nitrite is relatively stable under dry conditions, but it can slowly absorb oxygen and oxidize to sodium nitrate, and the aqueous solution is alkaline.

3. Appearance: Both are white. Under special circumstances, salt may also appear yellow or light blue, and sodium nitrite may also appear slightly yellow. Both are crystalline, and there is a certain difference in geometry under the microscope, but it cannot be distinguished with the naked eye.

4. Solubility: Sodium nitrite and table salt are easily soluble in water, deliquescence, and no odor.

5. Taste: Sodium nitrite has a slightly salty taste, salt salt has a heavy salty taste, and it is difficult to distinguish by taste when eating.

The difference between medical salt and edible salt

Difference: Normal saline is an injectable liquid with very low salt content. Edible salt is generally a solid processed with iodine and has a high salt content. Physiological saline refers to a sodium chloride solution whose osmotic pressure commonly used in physiological experiments or clinics is substantially equal to that of animal or human plasma. The purity and concentration requirements are strict, and there is no other addition. Of course, if you want to eat, it is meaningless and wasteful. Edible salt, commonly eaten salt, even refined salt, the purity is much worse, and some things such as iodized salt are intentionally added. The concentration of water is different.