Name 5 double salts.
Potash alum - K2SO4 Al2 ( SO4)3 .24H2O Dolomite - CaCO3.MgCO3
Alstonite, calcium barium carbonate - CaBa(CO3)2
Carnallite, KMgCl3·6H2O Potassium sodium tartrate hydrate - KNaC4H4O6·4H2O