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Dissociation constant

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Reference
Endpoint:
dissociation constant
Type of information:
other: handbook data or collection of data
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Qualifier:
according to guideline
Guideline:
other: OECD guideline 105
GLP compliance:
yes
Dissociating properties:
yes
No.:
#1
pKa:
0.011
Temp.:
25 °C
Remarks on result:
other: pH= 1.94
No.:
#2
pKa:
0
Temp.:
25 °C
Remarks on result:
other: pH= 6.22

Water solubility is 407 g/L at 20 °C.

Conclusions:
Based on the results, the dissociation constant of maleic anhydride (as maleic acid) is 5.95 x 10^-7 (pH = 6.22) at 25 ºC.
Executive summary:

In a GLP guideline study according to OECD 105, the dissociation constant of maleic anhydride was investigated. As maleic acid hydrolyses rapidly in water, the dissociation constant of maleic anhydride has been determined via its hydrolisation product – maleic acid.

Based on the results, the dissociation constant of maleic anhydride (as maleic acid) is 5.95 x 10^-7 (pH = 6.22) at 25 ºC.

Description of key information

In a GLP guideline study according to OECD 105, the dissociation constant of maleic anhydride was investigated. As maleic acid hydrolyses rapidly in water, the dissociation constant of maleic anhydride has been determined via its hydrolisation product – maleic acid.

Based on the results, the dissociation constant of maleic anhydride (as maleic acid) is 5.95 x 10^-7 (pH = 6.22) at 25 ºC.

Key value for chemical safety assessment

pKa at 20°C:
0

Additional information