Dipotassium phosphate (K₂HPO₄) (also dipotassium hydrogen orthophosphate; potassium phosphate dibasic) is the inorganic compound with the formula K₂HPO₄^.(H₂O)_x (x = 0, 3, 6). Together with monopotassium phosphate (KH₂PO₄^.(H₂O)_x), it is often used as a fertilizer, food additive, and buffering agent. It is a white or colorless solid that is soluble in water.

Dipotassium phosphate

Names
IUPAC name Potassium hydrogen phosphate
Other names Potassium monohydrogen phosphate Phosphoric acid dipotassium salt Potassium phosphate dibasic
Identifiers
CAS Number	7758-11-4 Y 16788-57-1 (trihydrate) Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:131527 N
ChEMBL	ChEMBL1200459 N
ChemSpider	22858 Y
ECHA InfoCard	100.028.940
EC Number	231-834-5
E number	E340(ii) (antioxidants, ...)
PubChem CID	24450
UNII	CI71S98N1Z Y RJK174X3TZ (trihydrate) Y
CompTox Dashboard (EPA)	DTXSID8035506
InChI InChI=1S/2K.H3O4P/c;;1-5(2,3)4/h;;(H3,1,2,3,4)/q2*+1;/p-2 Y Key: ZPWVASYFFYYZEW-UHFFFAOYSA-L Y InChI=1/2K.H3O4P/c;;1-5(2,3)4/h;;(H3,1,2,3,4)/q2*+1;/p-2 Key: ZPWVASYFFYYZEW-NUQVWONBAH
SMILES [K+].[K+].[O-]P([O-])(=O)O
Properties
Chemical formula	K2HPO4
Molar mass	174.2 g/mol
Appearance	white powder deliquescent
Odor	odorless
Density	2.44 g/cm3
Melting point	> 465 °C (869 °F; 738 K) decomposes
Solubility in water	149.25 g/100 mL (20 °C)
Solubility	slightly soluble in alcohol
Acidity (pKa)	12.4
Basicity (pKb)	6.8
Hazards
NFPA 704 (fire diamond)	1 0 0
Flash point	Non-flammable
Related compounds
Other cations	Disodium phosphate Diammonium phosphate
Related compounds	Monopotassium phosphate Tripotassium phosphate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

It is produced commercially by partial neutralization of phosphoric acid with two equivalents of potassium chloride:

H₃PO₄ + 2 KCl → K₂HPO₄ + 2 HCl