Bazı Substitue Fenollerin Ayrışma Sabitlerinin Asetonitril-Su Karışımlarında Potansiyometrik Metotla Tayini

Fenol, 2-metilfenol, 3-metilfenol, 4-metilfenol ve 4-etilfenol’ün ayrışma sabitleri %10-20-30 oranlarında hazırlanan asetonitril –su karışımında 25 o C potansiyometrik olarak elektrokimyasal hücrede elektrot ile tayin edilmiştir.Titrasyon çözeltilerinde iyonik şiddet KCl kullanılarak 0.1 mol dm−3 olarak ayarlanmıştır. Ayrışma sabitleri ticari bir program olan Hyperquad 2008 ile hesaplanmıştır. Elde edilen sonuçlar literatürdeki değerlerle uyumluluk göstermektedir.

Anahtar Kelimeler:

Fenol, asidik ayrışma sabiti, potansiyometrik yöntem

Determination of the Dissociation Constant of Some Substituted Phenols by Potentiometric Method in Acetonitrile-Water Mixtures

The dissociation constants of phenol, 2−methylphenol, 3−methylphenol, 4−methylphenol, and 4−ethylphenol have been determined by potentiometric titration in a electrochemical cell with glass electrode at 25 o C in water and in the mixtures of acetonitrile and water where the following volume fractions (before mixing) of acetonitrile were used: 0.10, 0.20, and 0.30. The ionic strength of the solutions was adjusted to be 0.1 mol dm−3 using KCl. The dissociation constants were calculated by using the commercial Hyperquad 2008 program. The obtained results are in good concordance withliterature values.

Keywords:

Phenols, acid dissociation constant, potentiometric method,

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Hakan Aktaş email: ahakan@fef.sdu.edu.tr