Polyprotic acid
3PO
4) is a triprotic acid. It can lose up to three hydrogen atoms to become phosphate (PO3−
4).
A polyprotic acid is an acid that has more than one acidic hydrogen atom. "Polyprotic" means "many protons", because the hydrogen ion is (normally) a single proton.[1]
Polyprotic acids are also grouped according to the exact number of hydrogen atoms. Diprotic acids like sulfuric and carbonic acid can give up two hydrogens; triprotic acids like phosphoric acid and citric acid can give up three. Acids with more than three acidic hydrogens are normally just called "polyprotic" instead of more specific names like "tetraprotic" or "pentaprotic".
Polyprotic Acid Media
Zinc, a typical metal, reacting with hydrochloric acid, a typical acid
Svante Arrhenius (* 19. Februar 1859 auf Gut Wik bei Uppsala; † 2. Oktober 1927 in Stockholm)
Acetic acid, a weak acid, donates a proton (hydrogen ion, highlighted in green) to water in an equilibrium reaction to give the acetate ion and the hydronium ion. Red: oxygen, black: carbon, white: hydrogen.
comparison of Lewis and Brønsted acid-base rxns
Hydrochloric acid (in beaker) reacting with ammonia fumes to produce ammonium chloride (white smoke)
This is an ideal titration curve for alanine, a diprotic amino acid. Point 2 is the first equivalent point where the amount of NaOH added equals the amount of alanine in the original solution.
Carbonated water (H2CO3 aqueous solution) is commonly added to soft drinks to make them effervesce.
Basic structure of an amino acid
Aspirin (acetylsalicylic acid) is a carboxylic acid.
References
- ↑ Flowers, Paul; Theopold, Klaus; Langley, Richard; Robinson, William R. (2019-02-14). "Polyprotic Acids". Chemistry 2e. OpenStax.