phosphoric acid

American  

noun

Chemistry.

1. any of three acids, orthophosphoric acid, H 3 PO 4 , metaphosphoric acid, HPO 3 , or pyrophosphoric acid, H 4 P 2 O 7 , derived from phosphorus pentoxide, P 2 O 5 , and various amounts of water.

---

phosphoric acid British  

noun

1. Systematic name: phosphoric(V) acid.  Also called: orthophosphoric acid.  a colourless solid tribasic acid used in the manufacture of fertilizers and soap. Formula: H 3 PO 4

2. any oxyacid of phosphorus produced by reaction between phosphorus pentoxide and water See also metaphosphoric acid pyrophosphoric acid hypophosphoric acid

---

phosphoric acid Scientific  

/ fŏs-fôr′ĭk /

1. A clear liquid, or a solid that forms colorless, rhombus-shaped crystals, that is used in fertilizers, detergents, food flavoring, and pharmaceuticals. Chemical formula: H ₃ PO ₄ .

---

Etymology

Origin of phosphoric acid

First recorded in 1785–95

Example Sentences

See Examples For:

phosphoric acid

Beyond biology, phosphoric acid is widely used in technologies such as batteries and fuel cells because of its exceptional ability to conduct protons.

From Science Daily ● Apr. 7, 2026

The tanker, which had been carrying a cargo of phosphoric acid, was identified as the Central Park by the vessel's company.

From Reuters ● Nov. 26, 2023

In 2013, it agreed to pay nearly $199,000 and to reduce air emissions from phosphoric acid production, while denying that it had polluted.

From Seattle Times ● Jul. 14, 2022

But gypsum stacks and wastewater from phosphoric acid production are exempt from the EPA's hazardous waste standards, which establish base federal criteria for managing waste from "cradle to grave."

From Salon ● Apr. 20, 2022

Instead of hydrochloric acid some French makers use phosphoric acid.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 5 "Gassendi, Pierre" to "Geocentric" by Various