Gold Chemistry Element

Author: nitin.p070

Element gold has been called as the most beautiful element because of its beauty which has made it desirable due to its attractive color and brightness also for its art work. Gold element is a dense, yellow, lustrous precious metal which belongs to group 11(1b) and period 6 of the periodic table. Gold is found in nature in comparatively pure form. Gold is one of the good conductors of heat and electricity and it is also soft and the most malleable and ductile of the elements.

Sources of Gold chemistry element: In nature, gold is found as the free metal and in tellurides. It is widely distributed metal and associated with pyrite or quartz. Gold is found in veins and in alluvial deposits. Depending on the location of the sample it occurs in sea water in the amount of 0.1 to 2 mg/ton.

Uses of gold chemistry element: It was used in the coinage. And it is the standard for many monetary systems. It is used for jewelry, dental work, plating and reflectors and Chlorauric acid is used in photography for toning silver images.

Characteristic properties of gold chemistry element:

Physical properties of gold chemistry element:

Density (g/cc): 19.3

Melting Point (°K): 1337.58

Boiling Point (°K): 3080

Appearance: soft, malleable, yellow metal

Debye Temperature (°K): 170.00

Pauling Negativity Number: 2.54

First Ionizing Energy (kJ/mol): 889.3

Oxidation States: 3, 1

Lattice Structure: Face-Centered Cubic (FCC)

Lattice Constant (Å): 4.080

Specific Gravity (20°C): 18.88

Atomic Radius (pm): 146

Atomic Volume (cc/mol): 10.2

Covalent Radius (pm): 134

Ionic Radius: 85 (+3e) 137 (+1e)

Specific Heat (@20°C J/g mol): 0.129

Fusion Heat (kJ/mol): 12.68

Evaporation Heat (kJ/mol): ~340

Chemical properties of gold chemistry element:

Gold is a yellow-colored metal, it may be black, ruby, or purple in finely divided form.

Chemistry element gold is the most malleable and ductile metal.

It is well known for the good conductor of electricity and heat.

Gold is not affected by exposure to air and to most reagents.

Gold is an inert metal and a good reflector of infrared radiation.

It is usually alloyed to increase its strength.

Extraction and refining of gold chemistry element:

Extraction:

Gold can be extracted by two ways, one is amalgamation and the other is cyanidation. This ore contains a variety of impurities, including zinc, copper, silver, and iron. Ore has to be mixed with mercury metal which combines with gold in the ore to form an amalgam. Further, this amalgam becomes a mixture of two or more metals in which one is mercury. Finally the gold amalgam is removed from the ore and it is heated to drive off the mercury to obtain pure gold.

Refining:

There are two methods for purification of gold. Those are Miller process and the Wohlwill process.

In the Miller process, all the impurities present in gold combine with gaseous chlorine more readily than gold does at temperatures equal to or greater than the melting point of the gold. Further impure gold is melted and gaseous chlorine is blown into the resulting liquid. Finally impurities form chloride compounds that separate into a layer on the surface of the molten gold. Miller process is most rapid and simple, but it produces gold of only about 99.5 percent purity where as Wohlwill process increases purity to about 99.99 percent by electrolysis.

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