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Phosphoric acid, also known as orthophosphoric acid or phosphoric(V) acid, is a weak acid with the chemical formula H3PO4.
P 2015 (OTTO) Polyphosphoric acid Cas 8017-16-1 - used as a strong drying and dehydrating agent. P 2015 (OTTO) Polyphosphoric acid Cas 8017-16-1 - used in microfabrication to etch silicon nitride selectively with respect to silicon dioxide.