Synonyms: Monopotassium phosphate or Potassium dihydrogen phosphate or prim.-Potassium phosphateH₂KO₄PKH₂PO₄ M_r 136.09CAS Number [7778-77-0]EC Number 231-913-4Merck 14,7659RTECS TC6615500MDL Number MFCD00011401PubChem Substance ID 24881812Purity ≥99.5%

pKa1 = 2.15 at 25°Cpka2 = 6.82 at 25°Cpka3 = 12.38 at 25°C

Melting point (starting material) 252.6°C (lit)

Measured pH range: 3.8 - 4.3 at 25°CMeasured Conductivity Range: 67.7 - 79.1 mS/cm at 25°CMeasured Refractive Index Range: 1.35356 - 1.35459 at 20°C

Total Impurities: Insoluble matter, passes filter testAl ≤0.0005%As ≤0.00001%Ba ≤0.0005%Bi ≤0.0005%Ca ≤0.001%Cd ≤0.0005%Cl ≤0.0005%Co ≤0.0005%Cr ≤0.0005% Cu ≤0.0005%Fe ≤0.0005%Li ≤0.0005%Mg ≤0.0005%Mn ≤0.0005%Mo ≤0.0005%N ≤0.001%Na ≤0.005%Ni ≤0.0005%Pb ≤0.0005%SO₄ ≤0.003%Sr ≤0.0005%Zn ≤0.0005%