32 g of nickel chloride hexahydrate is dissolved in 50 ml of water with stirring, the beaker is then immersed in an ice bath and the temperature is kept below 5°C. A slow addition, with stirring, of 70 mL of concentrated ammonium hydroxide solution is started. After which the solution is stirred for another 15 minutes and then 50 mL of ethanol is added to the solution to precipitate the product out. The mixture is placed in a refridgerator to crystallize all of the product out, after which it is filtered and washed with some ethanol. The product is left to dry with the suction of the vacuum pump.
NH4OH <–> NH3 + H2O
NiCl2 · 6H2O + 6 NH3 = [Ni(NH3)6]Cl2 + 6 H2O
Addition of the NH4OH
Crystallization of the product