Difference between revisions of "Platinum"

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*Make [[hexachloroplatinic acid]]
*Make [[chloroplatinic acid]]
*Make platinum electrodes
*Make platinum electrodes

Revision as of 18:45, 23 July 2017

Platinum,  78Pt
General properties
Name, symbol Platinum, Pt
Appearance Silvery white metal
Platinum in the periodic table


Atomic number 78
Standard atomic weight (Ar)
Group, block , -block
Period period 
Electron configuration
Physical properties
Melting point 2041.4 K ​(1768.3 °C, ​3214.9 °F)
Boiling point 4098 K ​(3825 °C, ​​6917 °F)
Density near r.t. 21.45 g/cm3
when liquid, at  19.77 g/cm3
Atomic properties
· references

Platinum is a chemical element with the chemical symbol Pt and the atomic number 78. It is a valuable and useful transition metal, part of the so called "platinum group metals".



Platinum is extremely resistant to organic and mineral acids. It will, however, dissolve extremely slowly in hot aqua regia, to give chloroplatinic acid.

Pt + 4 HNO3 + 6 HCl → H2PtCl6 + 4 NO2 + 4 H2O

It will also be attacked by molten alkali and cyanides.


Platinum is a lustrous, ductile, and malleable, silver-white metal. It is more ductile than gold, but less malleable.


Although it can be bought from precious metal stores, platinum is also found in certain electronics and car exhaust catalysts. Electrodes are sometimes coated with platinum. Platinum can be obtained along with silver in small amounts from capacitors obtained through electronic recycling.

Platinum bullion can be bought, which has the advantage of having purity expressed accurately.

In Australia, platinum is classified as Category II precursor chemical and purchasing it requires and EUD.[1]


Platinum can be extracted by dissolving it in aqua regia. The resulting chloroplatinic acid is converted to ammonium chloroplatinate by the addition of ammonium chloride, that can be reduced to platinum metal by heating it, usually in a hydrogen atmosphere. This results in a platinum sponge.




Being a noble metal, it is non-toxic, though some of its compounds should be handled with care.


No special storage is required for storing platinum, though platinum electrodes should be kept away from sulfur oxides which can "poison" it.


It's best to recycle platinum, considering it's a rare and expensive metal.


  1. http://www.sciencemadness.org/talk/files.php?pid=452422&aid=51570

Relevant Sciencemadness threads