![header thumbnail](/images/publishers\iso_cover.gif)
ISO 4281:1977
Current
The latest, up-to-date edition.
![header thumbnail](/images/publishers\iso_cover.gif)
Sodium hexafluorosilicate for industrial use — Determination of free acidity and total hexafluorosilicate content — Titrimetric method
Hardcopy , PDF , PDF 3 Users , PDF 5 Users , PDF 9 Users
English, French
01-03-1977
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.
Access your standards online with a subscription
Features
-
Simple online access to standards, technical information and regulations.
-
Critical updates of standards and customisable alerts and notifications.
-
Multi-user online standards collection: secure, flexible and cost effective.