By passing a current of hydrogen sulphide into an ammoniacal solution of (ordinary) ammonium molybdate, or by dissolving molybdenum trisulphide in ammonium sulphide solution, and concentrating by evaporating, blood-red crystals, appearing green by reflected light, of the normal salt (NH4)2MoS4 are obtained. They are not completely stable in air. The compound NH4MoS6.H2O has also been described.
By addition of a solution of ammonium hydrogen sulphide drop by drop to one of ammonium molybdate, the compound (NH4)HMo2S3O4 is precipitated as a reddish-yellow substance. Another mixed salt has the formula (NH4O)2MoS2. |