Aluminium

Chemical properties

   Under normal conditions of aluminum coated with a thin and solid oxide film and therefore does not react with classical oxidants: from H2O (t °); O2, HNO3 (without heating). This aluminum is practically immune to corrosion and is widely in demand because of modern industry. However, the destruction of the oxide film (eg, in contact with solutions of salts of ammonium NH4 +, hot alkali or as a result of amalgamation), aluminum acts as an active metal-reducing agent.

   It is easy to react with common substances:

   With oxygen:

   4Al + 3O2 = 2Al2O3

   With halogens:

   2Al + 3Br2 = 2AlBr3

   Other non-metals react when heated:

   with sulfur to form sulfide aluminum:

   2Al + 3S = Al2S3

   with nitrogen to form aluminum nitride:

   2Al + N2 = 2AlN

   carbon to form carbide aluminum:

   4Al + 3C = Al4S3

   Sulfide and carbide aluminum fully hydrolyzed:

   Al2S3 + 6H2O = 2Al (OH) 3 + 3H2S-

   Al4C3 + 12H2O = 4Al (OH) 3 + 3CH4-

   Complex substances:

   With water (after removing the protective oxide film, such as foiling or hot alkali solutions):

   2Al + 6H2O = 2Al (OH) 3 + 3H2-

   With alkali (with the formation tetragidroksoalyuminatov and other aluminates):

   2Al + 2NaOH + 6H2O = 2Na [Al (OH) 4] + 3H2-

   2 (NaOH • H2O) + 2Al = 2NaAlO2 + 3H2

   Easily soluble in hydrochloric and dilute sulfuric acid:

   2Al + 6HCl = 2AlCl3 + 3H2-

   2Al + 3H2SO4 (dilution) = Al2 (SO4) 3 + 3H2

   When heating dissolves in acids - oxidants, forming soluble salts of aluminum:

   2Al + 6H2SO4 (conc) = Al2 (SO4) 3 + 3SO2 + 6H2O

   Al + 6HNO3 (conc) = Al (NO3) 3 + 3NO2-+ 3H2O

   Recovers metals from their oxides (aluminothermy):

   8Al + 3Fe3O4 = 4Al2O3 + 9Fe

   2Al + Cr2O3 = Al2O3 + 2Cr