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ISO 4281:1977

Sodium hexafluorosilicate for industrial use — Determination of free acidity and total hexafluorosilicate content — Titrimetric method

Mar 1, 1977

General information

90.93     Nov 29, 2023

ISO

ISO/TC 47

International Standard

71.060.50  

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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.

Life cycle

NOW

PUBLISHED
ISO 4281:1977
90.93 Standard confirmed
Nov 29, 2023