Sodium Cobaltinitrite Solution

Dissolve 17gms. of the pure salt in 250
of water.
Alternately, the solution may be prepared as follows: Dissolve 7.5 gms. cobalt nitrate in 30ml. of water; dissolve 60gms. of sodium nitrite in 30ml. of water, mix the two solutions with vigorous stirring and add 15ml. of glacial acetic acid, stir, dilute to 250ml, allow to stand and filter.Make up new solution every 2-3 weeks.