69. When processing metal phosphide (II) obtained by weighing 9.1 g of a gas that ignites spontaneously in air. The combustion product is dissolved in water. The solution was neutralized and treated with excess of a solution of silver nitrate. Thus yellow precipitate weighing 42.0 g, soluble in acids. Identify metal.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)