ISO 4281:1977
Sodium hexafluorosilicate for industrial use; Determination of free acidity and total hexafluorosilicate content; Titrimetric method
- Standard No.
- ISO 4281:1977
- Release Date
- 1977
- Published By
- International Organization for Standardization (ISO)
- Latest
- ISO 4281:1977
- Scope
- With respect to the free acidity, applicable to products having contents, expressed as H2 SiF6 , equal to or more than 0,1 % (m/m). First, determination of the free acid contents by titration of an ice-cooled test portion with a standard volumetric sodium hydroxide solution in the presence of potassium nitrate and using bromothymol blue as indicator, then, followed by titration at near boiling temperature with standard volumetric sodium hydroxide solution to the appearance of a permanent blue colour.
ISO 4281:1977 history
- 1977 ISO 4281:1977 Sodium hexafluorosilicate for industrial use; Determination of free acidity and total hexafluorosilicate content; Titrimetric method
