Ammonium sulphate for industrial use — Determination of free acidity — Titrimetric method
NORMA vydaná dňa 1.4.1974
Označenie normy: ISO 2993:1974
Dátum vydania normy: 1.4.1974
Počet strán: 2
Približná hmotnosť: 6 g (0.01 libier)
Krajina: Medzinárodná technická norma
Kategória: Technické normy ISO
Description / Abstract: Applicable to products having a free acidity, expressed as H2 SO4 , equal to or more than 0.01 % (m/m). Dissolution of a test portion in Water and titration with standard volumetric sodium hydroxide solution in the presence of an indicator. The indicator must have a colour change in the pH range between 5.2 and 5.6. Has also been approved by the IUPAC.