Sodium

Name:Sodium (natrium, the German name)
Symbol:Na
Atomic Number:11
Atomic Mass:22.98976928
Density:23.78 g/cm^3
^{Melting Point:} 97.72 °C
Boiling Point: 883 °C
Electronic Configuration: 2.8.2
Group Number:1
Group Name:Alkali Metals
Standard state:solid at room temperature
Color:silvery-white
Classification:Metallic
Soap is generally a sodium salt of fatty acids. The importance of common salt to animal nutrition has been recognized since prehistoric times. The most common compound is sodium chloride.
Sodium salts impart a characteristic orange/yellow color to flames. The picture above shows the color arising from adding common salt (NaCl) to a burning mixture of potassium chlorate and sucrose.
Sodium is a Group 1 element. Group 1 elements are often referred to as the "alkali metals". The chemistry of sodium is dominated by the +1 ion Na⁺.

Isolation

Sodium would not normally be made in the laboratory as it is so readily available commercially. All syntheses require an electrolytic step as it is so difficult to add an electron to the poorly electronegative sodium ion Na⁺.

Sodium is present as salt (sodium chloride, NaCl) in huge quantities in underground deposits (salt mines) and seawater and other natural waters. It is easily recovered as a solid by drying.

Sodium chloride has a high melting point (> 800°C) meaning that it sould be expensive to melt it in order to carry out the electrolysis. However a mixture of NaCl (40%) and calcium chloride, CaCl₂ (60%) melts at about 580°C and so much less energy and so expense is required for the electrolysis.

cathode: Na⁺(l) + e^- → Na (l)

anode: Cl^-(l) → ¹/₂Cl₂ (g) + e^-

The electrolysis is carried out as a melt in a "Downs cell". In practice, the electrolysis process produces calcium metal as well but this is solidified in a collection pipe and returned back to the melt.