Copper(II) sulfate (CuSO4), is a common salt of copper. Copper sulfate exists as a series of compounds that differ in their degree of hydration. The anhydrous form is a pale green or gray-white powder, while the hydrated form is bright blue. The archaic name for copper(II) sulfate is “blue vitriol” or “bluestone”. The most common form of copper sulphate is in the pentahydrate form and there are over 100 manufacturers producing around 200,000 tonnes per annum. Approximately three-quarters of copper sulphate pentahydrate is used in agriculture, principally as a fungicide, but also for treating copper-deficient soils.
How to use copper sulfate for killing Moss:
Mix 5–8g per litre of water. apply this solution at a rate of 1 litre per 5m2.
How to use copper sulfate for treating algae in ponds, fish tanks and aquariums:
Dissolve 30g of copper sulfate and 30g of citric acid in 1 litre of water. For each 5 litres of pond water add 1 drop of the made up solution (this equates to 0.15ppm). Do not allow levels of copper to exceed 0.20 ppm.
How to use copper sulfate for controlling tree roots in drains & sewers
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Other uses for copper sulfate
Several chemical tests utilize copper sulfate as an indicator. In a flame test its copper ions emit a deep blue-green light. It is used in fehlings solution and Benedicts solution to test for reducing sugars, which reduce the soluble blue copper(II) sulfate to insoluble red copper 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 a beaker of copper sulfate solution: if it sinks within a certain time, then the patient has sufficient haemogloblin levels and is not anemic. If the blood floats or sinks too slowly, then the patient is iron-deficient and may be anemic.
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. However 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 colour. It can be used to plate metals with copper.
It finds use in agriculture as a fungicide. Mixed with lime it is called Bordeaux mixture, which is used to control fungus on plant leaves, grapes and other berries. Normally it is used as a 1% solution (100g copper sulfate & 100g Lime per 10 litres of water)
Its use as a 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.
Other applications include:
- Production of copper fungicides.
- Manufacture of Insecticides.
- Addition of copper to copper deficient soil.
- Soil sterilization.
- Preparation of Bordeaux and Burgundy mixtures.
- Mixed with ammonium carbonate to produce “Chestnut compound”.
- Preservative for pulp, wood and wooden structures.
- As a disinfectant, antiseptic, germicide and bacteriostat.
- Inhibits the growth of bacteria like Escherichia coli.
- Treatment of parasitic infections in aquarium fish.
- Removal of snails in aquariums.
- For the control and prevention of foot rot in cattle and sheep.
- As a growth stimulant for pigs and chickens.
- For the control and treatment of scum on lakes and ponds.
- As a molluscicide.
- As a preservative in glues.
- Control of bloom caused by algae in pools, ponds, reservoirs, spas etc
- Purification of gases.
- Mordant in vegetable dying industry.
- Laundry marking ink.
- As a dye for hair.
- Green colouration in fireworks and in flame tests.
- Preparation of diazo and aniline black dyes.
- Preparation of catalysts.
- Preparation of other copper compounds.
- As an electrolyte in plating and refining industries.
- As a flotation agent in mining.
- In the purification of butadiene.
- In the purification of petroleum oil.
- Etching agent in engraving especially zinc in the intaglio printmaking.
- In glass and ceramics industry to colour.
- Production of rayon.
- For blueing steel and the colouring of zinc and aluminium.
- For the control of concrete setting.
- Control and protection against lichen, fungus and moulds.
- In the preparation of Fehlings solution, Biuret Reagent and Benedicts solution.
- In the laboratory to demonstrate exothermic reactions where steel wool or magnesium and placed in an aqueous solution of copper sulphate.