Hydrofluoric Acid

HF = 20.01 (7664-39-3)

Content, minimum 40.0% m/m.

Clear, colourless liquid.

Loss on ignition: not more than 0.05% m/m; evaporate the hydrofluoric acid in a platinum crucible and gently ignite the residue to constant mass.

Assay Weigh accurately a glass-stoppered flask containing 50.0 mL of 1 M sodium hydroxide. Introduce 2 g of the hydrofluoric acid and weigh again. Titrate the solution with 0.5 M sulfuric acid, using 0.5mL of phenolphthalein solution as indicator.

1 mL of 1 M sodium hydroxide is equivalent to 20.01 mg of HF.

Store in a polyethylene container.