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Administrative data

Endpoint:
dissociation constant
Data waiving:
study technically not feasible
Justification for data waiving:
the study does not need to be conducted because the analytical method is not sensitive enough
other:
Justification for type of information:
Chloric acid belongs to the common strong acids with a pKa < 0. Reported pKa values for chloric acid are in the range from pKa = -1 to approx. pKa = -3. This means that the pH of an aqueous solution for a pKa determination should be brought into the range of pH < 0 with a very strong acid which is impossible. Acidity constants or dissociation constants, respectively, of such strong acids are normally obtained by thermodynamic and quantum chemical calculations.
Furthermore, potassium chlorate is incompatible with strong acids, decomposes and produces toxic chlorine and chlorine dioxide gas.

CONCLUSION:
An experimental determination of the dissociation constant of potassium chlorate is not possible due to its strong acidity and because the potassium chlorate decomposes on acidification.
Based on the available information, the pKa of potassium chlorate is in the range from
pKa = -1 to pKa = approx. -3.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2004
Report date:
2004

Materials and methods

Test material

Constituent 1
Chemical structure
Reference substance name:
Sodium chlorate
EC Number:
231-887-4
EC Name:
Sodium chlorate
Cas Number:
7775-09-9
Molecular formula:
ClHO3.Na
IUPAC Name:
sodium chlorate
Test material form:
solid: crystalline

Results and discussion

Applicant's summary and conclusion

Executive summary:

Chloric acid belongs to the common strong acids with a pKa < 0. Reported pKa values for chloric acid are in the range from pKa = -1 to approx. pKa = -3. This means that the pH of
an aqueous solution for a pKa determination should be brought into the range of pH < 0 with a very strong acid which is impossible. Acidity constants or dissociation
constants, respectively, of such strong acids are normally obtained by thermodynamic and quantum chemical calculations.
Furthermore, sodium chlorate is incompatible with strong acids, decomposes and produces toxic chlorine and chlorine dioxide gas.

CONCLUSION:
An experimental determination of the dissociation constant of sodium chlorate is not possible due to its strong acidity and because the sodium chlorate decomposes on acidification.
Based on the available information, the pKa of sodium chlorate is in the range from
pKa = -1 to pKa = approx. -3.

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