Cobalt Nitrate: Cobalt Oxide Dissolved in Nitric Acid (Thorpe 1912)

Cobalt oxide dissolves in nitric acid to give cobalt nitrate, a red salt that crystallises with six molecules of water and is very soluble. Result: red, deliquescent crystals of Co(NO3)2·6H2O. Source: Thorpe, Dictionary of Applied Chemistry, vol. 2 (1912), Cobalt. Not given: amounts, acid strength, how it is crystallised. Danger: nitric acid burns and gives brown fumes. Picture drawn by Youblob.