Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 603-094-7
CAS number: 125904-11-2
The pKa values for phosphoric acid were 2.38 and 7.06 at 25 °C.
The pKa value for 4 -nitrophenol was 6.99 at 22.1 °C. The reference
substance data were in good agreement with the literature values.
The pKa estimate obtained for DBS in the preliminary trial was
5.41. The preliminary results also indicated that a relatively weak NaOH
solution would be required. Therefore, a 0.001 N NaOH solution was
prepared and standardized for use in the definitive trial.
The calculated pK value for DBS is summarized below:
Table 1: pK Values of DBS at 20 °C
(CV = 1.27%)
Antilog (-pKa) = 1.91 x 10-7
1 Results were generated using Excel 2000 in the full precision
mode. Manual calculations may differ
Table 2: Determination of dissociation constant
% ionised = volume/equivalence point volume
% unionised = 1 - % ionised
pKa = pH – log(% ionised/% unionised)
Equivalence point = change in pH/change in volume is greatest
In a study performed in line with OCED Guideline 112 and in compliance
with GLP, the pKa value of dibromostyrene was determined to be 6.72 (SD
= 0.0855, CV = 1.27%) at 20 ºC.
Dibromostyrene does not contain any ionisable groups (basic or acidic).
Evaluation of dibromostyrene (a representative structure of the reaction
mass) using PALLAS 18.104.22.168: pKalc (CompuDrug Chemistry Ltd.) software
indicated that dibromostyrene contains not dissociating groups.
In accordance with Annex XI, point 2 (Testing is not technically
feasible) and in accordance with the ECHA guidance document, Guidance on
information requirements and chemical safety assessment chapter R.7a:
Endpoint specific guidance (November 2012) v. 2.0, testing for
dissociating properties is technically not possible as a consequence of
the properties of the substance. The three main constituents of the
multi-constituent substance, dibromostyrene, monobromostyrene and
tribromostyrene, cannot dissociate due to a lack of relevant functional
groups; a study to determine the dissociation constant is therefore
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
På den här webbplatsen används kakor. Syftet är att optimera din upplevelse av den.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again