... :7681-57-4 Appearance: white or light yellow crystalline powder Character: with smell of SO2,soluble in water,the solution is ... :7681-57-4 Appearance: white or light yellow crystalline powder Character: with smell of SO2,soluble in water,the solution is ... :7681-57-4 Appearance: white or light yellow crystalline powder Character: with smell of SO2,soluble in water,the solution is ...