Potassium phosphate monobasic

grade

anhydrous

Quality Level

200

assay

98-100.5% (calc. to the dried substance)

form

crystalline

quality

meets analytical specification of Ph. Eur., NF, E340

impurities

org. volatile impurities, complies (GC)
residual solvents, complies
≤0.001% heavy metals (as Pb)
≤0.04% KMnO₄ red. matter (as O)
≤0.2% in water insoluble matters

loss

≤1% loss on drying, 130 °C

pH

4.2-4.5 (20 °C, 5%)

pKa (25 °C)

(1) 2.15, (2) 6.82, (3) 12.38 (phosphoric acid)

mp

252.6 °C (lit.)

solubility

H₂O: soluble 4.5 parts
alcohol: insoluble

density

2.338 g/mL at 25 °C (lit.)

anion traces

chloride (Cl^–): ≤10 mg/kg
fluoride (F^–): ≤10 mg/kg
sulfate (SO₄^2-): ≤200 mg/kg

cation traces

As: ≤2 mg/kg
Cd: ≤1 mg/kg
Cu: ≤20 mg/kg
Fe: ≤10 mg/kg
Hg: ≤1 mg/kg
Na: ≤1000 mg/kg
Pb: ≤4 mg/kg
Zn: ≤20 mg/kg

suitability

complies for appearance of solution

SMILES string

[K+].OP(O)([O-])=O

InChI

1S/K.H3O4P/c;1-5(2,3)4/h;(H3,1,2,3,4)/q+1;/p-1

InChI key

GNSKLFRGEWLPPA-UHFFFAOYSA-M