Zinc 30 Zn 65.409(4)   Switch element to... actinium aluminium aluminum americium antimony argon arsenic astatine barium berkelium beryllium bismuth bohrium boron bromine cadmium caesium calcium californium carbon cerium cesium chlorine chromium cobalt copper curium darmstadtium dubnium dysprosium einsteinium erbium europium fermium fluorine francium gadolinium gallium germanium gold hafnium hassium helium holmium hydrogen indium iodine iridium iron krypton lanthanum lawrencium lead lithium lutetium magnesium manganese meitnerium mendelevium mercury molybdenum neodymium neon neptunium nickel niobium nitrogen nobelium osmium oxygen palladium phosphorus platinum plutonium polonium potassium praseodymium promethium protactinium radium radon rhenium rhodium roentgenium rubidium ruthenium rutherfordium samarium scandium seaborgium selenium silicon silver sodium strontium sulfur sulphur tantalum technetium tellurium terbium thallium thorium thulium tin titanium tungsten ununbium ununhexium ununoctium ununpentium ununquadium ununtrium uranium vanadium xenon ytterbium yttrium zinc zirconium Go adjacent...     Al Cu Zn Ga Ag Cd In

The essentials

Description 

Here is a brief description of zinc.

• Standard state: solid at 298 K
• Colour: bluish pale grey
• Classification: Metallic
• Availability:

  zinc is available in many forms including dust, foil, granules, powder, pieces, nanosize activated powder, shot, and a mossy form. Small and large samples of zinc foil, sheet, and wire can be purchased from Advent Research Materials via their web catalogue.

Zinc is a bluish-white, lustrous metal. It is brittle at ambient temperatures but is malleable at 100 to 150°C. It is a reasonable conductor of electricity, and burns in air at high red heat with evolution of white clouds of the oxide.

The picture above shows the result from burning a mixture of zinc metal powder and sulphur. Do not attempt this reaction unless are a professionally qualified chemist and you have carried out a legally satisfactory hazard assessment.

Zinc-deficient animals require 50% more food to gain the same weight of an animal supplied with adequate amounts of zinc. Zinc is not particularly toxic and is an essential element in the growth of all animals and plants.

Plating thin layers of zinc on to iron or steel is known as galvanising and helps to protect the iron from corrosion.

Isolation

Zinc metal is readily available commercially so it is not normally necesary to make it in the laboratory. Most zinc production is based upon sulphide ores. These are roasted in industrial plants to form zinc oxide, ZnO. This may be reduced with carbon to form zinc metal, but in practice ingenious technology is required to ensure that the resulting zinc does not contain oxide impurities.

ZnO + C → Zn + CO

ZnO + CO → Zn + CO₂

CO₂ + C → 2CO

The other type of extraction is electrolytic. Dissolution of crude zinc oxide, ZnO, in sulphuric acid gives zinc sulphate, ZnSO₄ in solution. Cadmium is an impurity and this is removed as a precipitate of cadmium sulphate by the addition of zinc dust. Electrolysis of the ZnSO₄ solution using aluminium cathodes and lead alloyed with silver anodes gives pure zinc metal coated on the aluminium. Oxygen gas is liberated at the anode.

Very pure zinc may be formed from crude zinc by zone refining and single crystals can be grown with purities of better than 99.9999%.

	Web webelements.com