... crystalline powder Character: with smell of SO2,soluble in water,the solution is acidic.Usages: Fiber, photo ,pharmacy,chemical ,petroleum ... crystalline powder Character: with smell of SO2,soluble in water,the solution is acidic.Usages: Fiber, photo ,pharmacy,chemical , ... crystalline powder Character: with smell of SO2,soluble in water,the solution is acidic.Usages: Fiber, photo ,pharmacy,chemical , ...