Potentiometric Determinations. Potentiometric titrations
at the University of Arizona were carried out with the aid of a
Beckman (Fullerton, CA) Model Phi 72 pH meter with a Corning
(Corning, NY) 476280 glass electrode and Corning 476350
calomel reference electrode. A 1 mm inner diameter Teflon tube
filled with agarose, saturated with KNO3, was used as a salt
bridge between the reference electrode and the titration vessel.
Titrations at Brandon University were carried out with the aid
of a Fisher (Pittsburgh, PA) Accumet #50 pH meter, a Sargent
(Skokie, IL) glass-calomel combination electrode, and a Metrohm
(Herisau, Switzerland) 10 mL microburet. Titrations were
performed in a sealed, jacketed vessel under nitrogen at 25 (
0.1 °C. All titrations were carried out at an ionic strength of
0.1, with either potassium chloride or potassium nitrate as a
background electrolyte.
The slope of the pH meter response was adjusted using
standard pH 4.00 and 10.00 buffers. Calibration of the pH
meter was performed by titrating a 0.1000 M standard hydrochloric
acid solution with the standard KOH solution. Linear
plots of the measured pH versus calculated -log[H] in the acidic
and basic regions were used to convert measured pH values to
hydrogen ion concentrations. A Gran plot was used to estimate
the amount of carbonate contamination in the base, which was
usually between 0.5% and 1% (15-17). A Gran plot of the
calibration data in the basic region was also used to determine
an experimental value for the ion product for water at the ionic
strength employed in the potentiometric titrations.
Metal-ligand formation constants were determined as follows.
Solutions containing only the mercuric ion and glu-
Potentiometric Determinations. Potentiometric titrations
at the University of Arizona were carried out with the aid of a
Beckman (Fullerton, CA) Model Phi 72 pH meter with a Corning
(Corning, NY) 476280 glass electrode and Corning 476350
calomel reference electrode. A 1 mm inner diameter Teflon tube
filled with agarose, saturated with KNO3, was used as a salt
bridge between the reference electrode and the titration vessel.
Titrations at Brandon University were carried out with the aid
of a Fisher (Pittsburgh, PA) Accumet #50 pH meter, a Sargent
(Skokie, IL) glass-calomel combination electrode, and a Metrohm
(Herisau, Switzerland) 10 mL microburet. Titrations were
performed in a sealed, jacketed vessel under nitrogen at 25 (
0.1 °C. All titrations were carried out at an ionic strength of
0.1, with either potassium chloride or potassium nitrate as a
background electrolyte.
The slope of the pH meter response was adjusted using
standard pH 4.00 and 10.00 buffers. Calibration of the pH
meter was performed by titrating a 0.1000 M standard hydrochloric
acid solution with the standard KOH solution. Linear
plots of the measured pH versus calculated -log[H] in the acidic
and basic regions were used to convert measured pH values to
hydrogen ion concentrations. A Gran plot was used to estimate
the amount of carbonate contamination in the base, which was
usually between 0.5% and 1% (15-17). A Gran plot of the
calibration data in the basic region was also used to determine
an experimental value for the ion product for water at the ionic
strength employed in the potentiometric titrations.
Metal-ligand formation constants were determined as follows.
Solutions containing only the mercuric ion and glu-
การแปล กรุณารอสักครู่..