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Dissociation constant

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dissociation constant
Type of information:
experimental study
Adequacy of study:
key study
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Principles of method if other than guideline:
Conductometric Methods
GLP compliance:
not specified
Dissociating properties:
25 °C

Measurements in solution of base only.

Executive summary:

N,N-dimethyl-1-phenylmethanamine has a pKa value of 8.91 (Perrin, 1965).

Description of key information

Benzyldimethylamine has a measured pKa value of 8.91 (conductometric method; published literature, Perrin, 1965).

Under environmentally-relevant pH range of 5 to 9, the ionised species N+ will be the main form below the pKa, between 100% and 90% up to pKa-1 = 7,9. In alkaline media (pH 8-9) a mixture of both ionised and non-ionised forms will be present. The non-ionised form will not exist >90% in natural conditions.

Key value for chemical safety assessment

pKa at 20°C:

Additional information

A reliable publicly available data source reports an experimentally measured dissociation constant for the substance. Therefore it was considered as key.