Phosphoric acidH₃PO₄

H3PO4 • 97.994 g·mol⁻¹

acidcovalentliquidCAS 7664-38-2PubChem 1004 →
H₃PO₄H3PO497.9940 g·mol⁻¹
Molar mass97.994 g·mol⁻¹calc 97.994 • Atomic weights: CIAAW 2021 (conventional atomic weights)
FormulaH₃PO₄H3PO4
Classacid • covalentliquid
Composition — H₃PO₄
ElementCountMass (g/mol)Mass %
H33.0243.09%
P130.97431.61%
O463.99665.31%

Physical properties

State at STP
liquid
Density
1.88 g·cm⁻³ (liquid (100%) at 20 °C, 1 atm)
Melting point
315.15 K (1 atm)
Boiling point
431 K (decomposes)

Structure & bonding

Tetrahedral PO4 with three OH and one P=O. Triprotic weak-to-moderate acid.

Occurrence & preparation

Wet process: phosphate rock + H2SO4.

Uses

  • Fertilizer
  • Food acid (regulated)

Safety

Corrosive; causes burns.

Consult current SDS. — consult current SDS before handling.

Constituent elements

Related reactions

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