Copper forms compounds in the oxidation states +1 and +2 ( trivalent copper survives no more than a few seconds in an aqueous solution). Copper sulfate is the common name for the blue crystalline cupric sulfate, in which copper has valence +2. It may also refer to cuprous sulfate (Cu2SO4), in which copper has valence +1. It is soluble in water but insoluble in alcohol. It usually crystallizes as a pentahydrate compound containing five molecules of water (CuSO4×5H2O) and is known in commerce as blue vitriol. It is prepared by the treatment of copper oxides with sulfuric acid.
Cupric sulfate is the most important salt of copper. Cupric sulfate is utilized chiefly for agricultural purposes, as a pesticide, germicide, feed additive, and soil additive. It is also used as a raw material in the preparation of other copper compounds, electrolyte for batteries and electroplating baths, and in medicine as a locally applied fungicide, bactericide, and astringent. It also finds wide use in the preparation of pigments.
Copper sulphate, blue stone, blue vitriol are all common names for pentahydrated cupric sulphate, CuSO45H2O, which is the best known and the most widely used of the copper salts. Indeed it is often the starting raw material for the production of many of the other copper salts. Today in the world there are more than 100 manufacturers and the world’s consumption is around 200,000 tonnes per annum of which it is estimated that approximately three-quarters is used in agriculture, principally as a fungicide.
Copper forms compounds in the oxidation states +1 and +2 ( trivalent copper survives no more than a few seconds in an aqueous solution). Copper sulfate is the common name for the blue crystalline cupric sulfate, in which copper has valence +2. It may also
In organic synthesis
Copper sulfate is employed in organic synthesis.The anhydrous salt catalyses the transacetalization in organic synthesis. The hydrated salt reacts with potassium permanganate to give an oxidant for the conversion of primary alcohols.
In school chemistry demonstrations
Copper sulfate is a commonly included chemical in children’s chemistry sets and is often used in high school crystal growing. and copper plating experiments. Due to its toxicity, it is not recommended for small children. Copper sulfate is often used to demonstrate an exothermic reaction, in which steel wool or magnesium ribbon is placed in an aqueous solution of CuSO4. It is used in school chemistry courses to demonstrate the principle of mineral hydration. The pentahydrate form, which is blue, is heated, turning the copper sulfate into the anhydrous form which is white, while the water that was present in the pentahydrate form evaporates. When water is then added to the anhydrous compound, it turns back into the pentahydrate form, regaining its blue color.
As an herbicide, fungicide, pesticide
Copper sulfate pentahydrate is a fungicide. Mixed with lime it is called Bordeaux mixture to control fungus on grapes and other berries.Its use as an herbicide is not agricultural, but instead for control of invasive exotic aquatic plants and the roots of other invasive plants near various pipes that contain water. A dilute solution of copper sulfate is used to treat aquarium fish of various parasitic infections, and is also used to remove snails from aquariums. However, as the copper ions are also highly toxic to the fish, care must be taken with the dosage. Most species of algae can be controlled with very low concentrations of copper sulfate.
Several chemical tests utilize copper sulfate. It is used in Fehling’s solution and Benedict’s solution to test for reducing sugars, which reduce the soluble blue copper(II) sulfate to insoluble red copper(I) oxide. Copper(II) sulfate is also used in the Biuret reagent to test for proteins.
Copper sulfate is also used to test blood for anemia. A drop of the patient’s blood is dropped into an aqueous solution of copper sulfate solution: if it sinks within a certain time, then the patient has sufficient hemoglobin levels and is not anemic. If the blood drop floats or sinks slowly, then the patient is iron-deficient and may be anemic.
In a flame test, its copper ions emit a deep blue-green light, much more blue than the flame test for barium.
Other applications include hair dyes, coloring glass, and processing of leather and textiles. Another more commonly witnessed use is to give pyrotechnics a green coloring
Specification Of Copper Sulphate