Copper (II) sulfate: properties, preparation and use
In the building materials store, you saw a bucket with the name Mineral Dye unknown to you. Curiosity takes over, and your hand reaches out to him. We read the composition: "Lime, kitchen salt, etc., etc. ..." And what else is copper sulfate ?! Others would only give up on it, but not you, you probably want to know more about it, so the topic of today's article will be copper sulfate.
Due to the variable valence of copper, there are two of its sulfates in chemistry - I and II. Now we will talk about the second sulfate. It is an inorganic binary compound and is a copper salt of sulfuric acid. This copper sulfate (formula CuSO4) is also called copper sulphate.
It is a non-volatile, colorless, opaque and highly hygroscopic, odorless substance.However, the properties of copper sulfate crystalline hydrates themselves are significantly different from its characteristics (as substances). They have the form of transparent non-hygroscopic crystals, in which there are various shades of blue (photo above) and a bitter-metallic taste. Copper sulphate is also highly soluble in water. If you crystallize its aqueous solutions, you can get copper sulfate (photo). Hydration of anhydrous copper sulphate is an exothermic reaction, in which there is a significant heat release.
In industry, it is obtained contaminated by dissolving copper and copper waste in dilute sulfuric acid, which, in addition, is flushed with air.
Also copper sulfate can be obtained in the laboratory in several ways at once:
- Sulfuric acid + copper (when heated).
- Sulfuric acid + copper hydroxide (neutralization).
For the purification of copper sulfate obtained by such methods, recrystallization is most often used — it is dipped in boiling distilled water and kept on fire until the solution becomes saturated. Then it is cooled to +5.aboutC and filter the resulting precipitate, resembling crystals.However, there are methods for more thorough purification, but they already need other substances.
Copper sulphate: application
With the help of anhydrous copper sulphate, ethanol is absolutized and gases are dried, and it also serves as a moisture indicator. In construction, an aqueous solution of copper sulphate neutralizes the effects of leaks, eliminates rust stains and removes salts from plastered, brick and concrete surfaces, and also prevents the wood from rotting. In the agricultural sector, copper sulfate formed from copper sulfate serves as an antiseptic, fungicide and copper-sulfur fertilizer. The solutions of this substance (with its different concentration) disinfect the plants, trees and soil. Bordeaux liquid, well-known to farmers, also partly consists of copper sulfate. He is also one of the ingredients that make up the mineral paints. Not without it and in the production of acetate fibers. Also bluestone is known as food additive E519, used as a fixative for coloring and preservative. Also, a solution of blue vitriol can be detected zinc, manganese in aluminum alloys and stainless steel: if they containthe above impurities, then in contact with this solution on their surface will appear red spots.
Copper (II) sulfate is little known per se, but everyone has heard about the product of its reaction with water - copper sulphate. And, as you can see, it is of great benefit.