Monopotassium phosphate Two unit cells of MKP viewed close to the b axis Names IUPAC name Potassium dihydrogen phosphate Other names Potassium phosphate monobasic Phosphoric acid, monopotassium salt Identifiers CAS Number 7778-77-0 Y 3D model (Jmol) Interactive image ChEMBL ChEMBL1200925 N ChemSpider 22914 N ECHA InfoCard 100.029.012 EC Number 231-913-4 PubChem 516951 RTECS number TC6615500 UNII 4J9FJ0HL51 Y InChI InChI=1S/3K.H3O4P/c;;;1-5(2,3)4/h;;;(H3,1,2,3,4)/q3*+1;/p-3 Y Key: LWIHDJKSTIGBAC-UHFFFAOYSA-K Y InChI=1/3K.H3O4P/c;;;1-5(2,3)4/h;;;(H3,1,2,3,4)/q3*+1;/p-3 Key: LWIHDJKSTIGBAC-DFZHHIFOAX SMILES [K+].OP(O)([O-])=O Properties Chemical formula KH2PO4 Molar mass 136.086 g/mol Appearance White powder deliquescent Odor odorless Density 2.338 g/cm3 Melting point 252.6 °C (486.7 °F; 525.8 K) Boiling point 400 °C (752 °F; 673 K) (decomposes) Solubility in water 22.6 g/100 mL (20 °C) 83.5 g/100 mL (90 °C) Solubility slightly soluble in ethanol Acidity (pKa) 6.86[1] Basicity (pKb) 11.9 Refractive index (nD) 1.4864 Structure Crystal structure tetragonal[2] Space group I42d Lattice constant a = 0.744 nm, b = 0.744 nm, c = 0.697 nm Hazards Safety data sheet External MSDS NFPA 704 0 1 0 Flash point Non-flammable Lethal dose or concentration (LD, LC): LD50 (median dose) 3200 mg/kg (rat, oral) Related compounds Other cations Monosodium phosphate Monoammonium phosphate Related compounds Dipotassium 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