Sodium Potassium Cobalti-nitrite, NaK₂Co(NO₂)₆

Sodium Potassium Cobalti-nitrite, NaK₂Co(NO₂)₆.H₂O, results on adding a solution of sodium cobalti-nitrite to a solution of potassium chloride acidified with acetic acid. The salt is obtained as a yellow precipitate, one part of which requires 20,000 parts of water for its complete solution. The conditions given must be carefully adhered to, otherwise precipitates of varying composition are obtained according to the relative proportions of sodium and potassium.