Registration Dossier
Registration Dossier
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EC number: 233-071-3 | CAS number: 10028-18-9
Dissociation constant
Administrative data
Link to relevant study record(s)
- Endpoint:
- dissociation constant
- Type of information:
- calculation (if not (Q)SAR)
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- accepted calculation method
- Qualifier:
- according to guideline
- Guideline:
- other: Calculation method
- Principles of method if other than guideline:
- Theoretical calculation. Dissociation Constant of NiF2 is derived from pKa of hydrofluoric acid, HF, and of Nickel hydroxide, Ni(OH)2 and the correspondent water solubility.
- Dissociating properties:
- yes
- No.:
- #1
- pKa:
- ca. 0.019
- Temp.:
- 20 °C
- Remarks on result:
- other: Calculated
- Conclusions:
- The calculated Ks for Nickel fluoride is 1.927exp-2, i.e. a pKa=0.01927
Reference
Dissociation constant was calculated.
pKa Hydrofluoric acid = 3.15
pKa Nickel hydroxide = 13.80
Nickel hydroxide value is very close to 14 indicating that it is a strong basis and the corresponent ion (Ni2 +) has no further equilibrium in solution.
pKa of hydrofluoric acid is only 3.15 indicating that it is rather a weak acid. Ion F- is prone to be in equilibrium with its undissociated form HF.
Description of key information
pKa 0.01927 at 20 °C
Key value for chemical safety assessment
- pKa at 20°C:
- 0.019
Additional information
Calculated from pKa + water solubility of Hydrofluoric Acid and pKb + water solubility of Nickel hydroxide
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