A solution of sulphur trioxide in sulphuric acid; the sulphur trioxide concentration is a minimum of 25%; used in the chemical industry.
| Volume of sulfuric acid (H2SO4) |
% weight |
105.6– 107.2 |
SOP-A-172 |
| Free sulphur trioxide content (SO3) |
% weight |
25 – 32 |
SOP-A-172 |
| Colour (Hazen), max. |
HJ |
– |
SOP-A-172 |
| Opacity at 560 nm, max. |
ZF |
– |
SOP-A-172 |
| Iron (Fe), max. |
% weight |
0,06 |
SOP-A-172 |
| Appearance |
|
|
SOP-A-172 |