Dissoudre 10,21 (± 0,01) g d'hydrogéno-phthalate de potassium (KHC8 O4 H4 ) dans de l'eau.
Dissolve 10,21 ± 0,01 grams of potassium hydrogen phthalate (KHC8 O4 H4 ) in water, transfer without loss into a 1 000-ml graduated flask, make up to the mark and mix.