Hydrofluoric acid has a weak acidity. Acid strength and corrosiveness are completely two concepts. Acidity is the electrophilic nature, and corrosiveness generally refers to the oxidizing ability. For example, sulfuric acid, even strong acid is strongly corrosive, while hydrofluoric acid is weak acid but strong corrosive.
All-silicon in water includes soluble silica and insoluble silica. Insoluble silica is chemically inactive and hydrofluoric acid is the only acid that dissolves it well.
Heat the acidified water sample on a boiling water bath, convert the insoluble silica to fluorosilicic acid with hydrofluoric acid, and then add a solution of aluminum trichloride to mask the excess hydrofluoric acid and place all the fluorosilicon. The acid dissociates to make silicon a soluble silica. The silicon silicon yellow method was used to determine the total silicon content.