Wijs solution for determination of the iodine number c(ICl)

Product Information

HS Code3822 19 00
Quality LevelMQ200


Amount-of-substance concentration0.0994 – 0.1006
Measurement uncertainty+/- 0.0004
TraceabilityNIST SRM
Accreditation: This volumetric solution is analyzed by our calibration laboratory D-K-15185-01-00 which is accredited according to
DIN EN ISO/IEC 17025 for analysis of amount-of-substance concentrations in volumetric solutions by DAkkS (Deutsche Akkreditierungsstelle – German National Accreditation Body). The accreditation certificate can be found at www.sigmaaldrich.com/ISO17025.
The concentration is determined by volumetric titration and refers to 20°C.
The amount-of-substance concentration of this volumetric solution is determined with standardized sodium thiosulfate solution (article number 1.09147). The sodium thiosulfate solution is standardized and traceable to a primary standard reference material (SRM) from the National Institute of Standards and Technology, Gaithersburg, USA (NIST SRM 136 potassium dichromate) by means of volumetric standard potassium iodate (article number 1.02404), certified reference material according to ISO 17034, analyzed by our accredited calibration laboratory of Merck KGaA, Darmstadt, Germany according to DIN EN ISO/IEC 17025. The uncertainty is expressed as expanded measurement uncertainty with a coverage factor k=2 covering a confidence level of 95%.
Note: The titer is a correction factor to correct for variations of the volumetric solution, the titration equipment, the temperature and other laboratory conditions. For correct titration results it is recommended to determine a titer with the laboratory specific equipment and under laboratory specific conditions directly after opening a new bottle and at regular time intervals.

Safety Information

Hazard Pictogram(s)Hazard Pictogram(s)
Hazard Pictogram(s)
Hazard Statement(s)H226: Flammable liquid and vapour.
H314: Causes severe skin burns and eye damage.
Precautionary Statement(s)P210: Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
P233: Keep container tightly closed.
P240: Ground and bond container and receiving equipment.
P280: Wear protective gloves/ protective clothing/ eye protection/ face protection/ hearing protection.
P303 + P361 + P353: IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water.
P305 + P351 + P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
Signal WordDanger
Storage class3 Flammable liquids
WGKWGK 2 obviously hazardous to water
Inorganic acids and anhydrides thereof should first be diluted or hydrolyzed by stirring carefully into ice water and then neutralized (protective gloves, fume cupboard!) with sodium hydroxide solution (Cat. No. 105587). Before filling into container D, check the pH with pH universal indicator strips (Cat. No. 109535). Fuming sulfuric acid should be carefully stirred dropwise into 40 % sulfuric acid (Cat. No. 109286). Ensure that plenty of ice is available for cooling! When sufficiently cool, treat the highly concentrated sulfuric acid as described above. Analogous to this procedure, other anhydrides can be converted into their corresponding acids. Acid gases (e.g. hydrogen halide, chlorine, phosgene, sulfur dioxide) can be introduced into dilute sodium hydroxide solution and after neutralization disposed of in container D.