Heavy Metals

Notes

Transition Elements

Transition elements are d-block elements. The elements in which the last electron enters the 'd' orbital of the penultimate shell is known as d-block. d-block elements lie in the middle of the periodic table. The elements having partly filled d-orbital in the penultimate shell in their atoms or in their stable oxidation states are called transition elements or transition metals. Transition metal compounds are paramagnetic (attracted towards magnetic field). It is due to the presence of unpaired d - electrons in metal ions.

Iron

Iron is mainly extracted from its ore haematite ( Fe2O3). The blast furnace is a tall cylindrical furnace made up of steel and internally lined with fire resistant bricks. Steel contains the intermediate amount of carbon ( 0.25% to 2.5%). When iron is exposed to moist air, a red-brown substance forms on its surface is known as rust.

Introduction to Copper

Copper is mainly extracted from sulphide ore i.e. Copper iron pyrite. Copper is used in making utensils, used in making alloys like brass {Cu+Zn}, bronze [Cu+Sn}. Copper is used as corrosive reagent as well as an antibacterial particle. Copper is important for applications such as food preparation, hospitals, coins, doorknobs and plumbing systems.

Introduction to Zinc

Zinc is one of the widely used metal in the entire world. Zinc is mostly used for galvanizing other metals in order to protect them from rusting. Most of it is used in die-casting which are important in automobile electrical and hardware industries. Zinc is found in several ores in the form of zinc blende and calamine. The principal mining areas are in China, Australia, and Peru. Commercially, zinc is obtained from its ores by concentrating and roasting the ore, then reducing it to zinc by heating with carbon or by electrolysis. World production is more than 11 million tons a year.

Introduction to Mercury

Mercury is extracted from cinnabar (HgS). Mercury is the heaviest metal at ordinary temperature. It is silvery-white liquid as well as poisonous in nature. It is used in thermometer, barometer. It is also used to make an amalgam. Mercury is an interesting thing to study upon for a very long time as a heavy liquid metal. However, because of its toxicity, many uses of mercury are being phased out or are under review.

Introduction to Silver

Silver is a member of Group IB of the periodic table, which includes copper, silver, and gold. Silver is extracted from Argentine. Silver is a good conductor of heat and electricity and is malleable and ductile. Silver nitrate forms stain on the skin due to decomposition of silver and hence, used for making tattoos. Silver nitrate is used for silvering the mirror.

Compounds of Copper

Blue vitrol is also known as copper sulphate pentahydrate, roman vitrol, salzburg vitrol, copper sulphate 5-water etc.blue vitrol contain 25.45% copper, 4.04% hydrogen, 57.67% oxygen and 12.84% sulphur.Blue vitrol is used in electroplating as well as electrorefining of metal.

Compounds of Zinc

Zinc oxide is white fibrous powder,insoluble in water used as white paint. Zinc oxide constitutes 19.66% of oxygen and 80.34% of zinc in it.Zinc sulphate constitute 4.92% Hydrogen, 61.20% oxygen, 11.15% sulphur and 22.74% zinc in it.