Copper(II) sulfate

Chemical Properties

Copper sulfate, also known as cupric sulfate, is a versatile compound used in various industries. As an intermediate and wood preservative, it plays a crucial role in the production of copper compounds. Its applications extend to the detection and removal of trace amounts of water from alcohols and organic compounds. In agriculture, copper sulfate serves as a fungicide, algaecide, bactericide, herbicide, and molluscicide. It is employed to control bacterial and fungal diseases in crops and as a protective fungicide in leaf applications and seed treatments.

Uses

Definition

A compound prepared as the hydrate by the action of dilute sulfuric acid on copper( II) oxide or copper(II) carbonate. On crystallization, blue triclinic crystals of the pentahydrate (blue vitriol, CuSO4.5H2O) are formed. Industrially copper(II) sulfate is prepared by passing air through a hot mixture of dilute sulfuric acid and scrap copper. The solution formed is recycled until the concentration of the copper(II) sulfate is sufficient. Copper(II) sulfate is readily soluble in water. The monohydrate (CuSO4.H2O) is formed at 100°C and the anhydrous salt at 250°C. Anhydrous copper( II) sulfate is white; it is extremely hygroscopic and turns blue on absorption of water. It decomposes on heating to give copper(II) oxide and sulfur(VI) oxide. Copper(II) sulfate is used as a wood preservative, a fungicide (in Bordeaux mixture), and in the dyeing and electroplating industries.

General Description

A white or off-white solid. Melting point 200°C with decomposition. Non-combustible.

Air & Water Reactions

Soluble in water.

Hazard

Toxic; highly irritant.

Health Hazard

Workers who accidentally ingest copper sulfate experience abdominal pain and cramps, burning sensation, corrosive effects, nausea, vomiting, loose bowel movement, and a metallic taste. Exposures to copper sulfate by ingestion or skin absorption cause severe irritating effects to the eyes and skin The aerosol is irritating to the respiratory tract, and effects on the blood, kidneys and liver result in hemolytic anemia, kidney impairment, liver impairment, and shock or collapse. At large doses, accidental intake of copper sulfate causes renal failure, comatose, and even death. Long-term exposure to copper sulfate may lead to liver damage, lung diseases, and decreased female fertility.

Trade name

AGRITOX?; BASICOP?; BCS COPPER FUNGICIDE?; BSC FLOWABLE?[C]; COPSIN?; CP BASIC SULFATE?; CUPROFIX?; FUNGI-SPERSE II[C]; SULTRACOB?; TNCS? 53; TRIANGLE?

Safety Profile

A human poison by ingestion. An experimental poison by ingestion, subcutaneous, parenteral, intravenous, and intraperitoneal routes. Human systemic effects by ingestion: gastritis, Qarrhea, nausea or vomiting, damage to kidney tubules, and hemolysis. Questionable carcinogen with experimental tumorigenic data. An experimental teratogen. Other experimental reproductive effects. Mutation data reported. Reacts violently with hydroxylamine, magnesium. See also COPPER COMPOUNDS and SULFATES. When heated to decomposition it emits toxic fumes of SOx

storage

Workers should keep copper sulfate stored in a cool, dry area with suffi cient ventilation. It should be kept away from alkalis, magnesium, ammonia, acetylene, and sodium hypobromite.

Shipping

UN3288 Toxic solids, inorganic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required. UN3077 Environmentally hazardous substances, solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required.

Purification Methods

After adding 0.02g of KOH to a litre of nearly saturated aqueous solution of the sulfate, it is left for two weeks, then the precipitate is filtered on to a fibreglass filter with pore diameter of 5-15 microns. The filtrate is heated to 90o and allowed to evaporate until some CuSO4.5H2O crystallises out. The solution is then filtered hot and cooled rapidly to give crystals which are freed from mother liquor by filtering under suction [Geballe & Giauque J Am Chem Soc 74 3513 1952]. Alternatively crystallise the sulfate from water (0.6mL/g) between 100o and 0o. The pentahydrate is slowly efflorescent, losing 2H2O at 30o, two more H2O are lost at 110o and a white anhydrous powder (dessicant) is obtained on heating above 250o.

Incompatibilities

Aqueous solution is an acid. May form explosive materials on contact with acetylene and nitromethane. Incompatible with strong bases; hydroxylamine, magnesium; zirconium, sodium hypobromite, hydrazine.

Waste Disposal

Copper-containing soluble wastes can be concentrated through the use of ion exchange, reverse osmosis, or evaporators to the point where copper can be electrolytically removed and sent to a reclaiming firm. If recovery is not feasible, the copper can be precipitated through the use of caustics and the sludge deposited in a chemical waste landfill Add soda ash to waste CuSO4 solution; let stand 24 hours. Decant and neutralize solution before flushing to sewer. Landfill sludge.

Precautions

During handling and use of copper sulfate, students and occupational workers should wear safety glasses and should not breathe the material in powder form. Copper sulfate is an environmental pollutant and must be carefully incorporated when used in its varied applications. Workers should wear protective clothing, goggles, impermeable gloves, and rubber boots to avoid skin contact