Determination of primary and secondary standards for pH measurements in N-methylacetamide and its 0.50 mass fraction in admixture with water, with characterization of appropriate salt bridges

Following the IUPAC criteria, four primary standards (pHPS) and three secondary standards (pHSS) have been determined at various temperatures using Harned's reversible cell and Baucke's nonreversible cell, respectively, the solvent media Z studied being N-methylacetamide and its mixture with water at 0.50 mass fraction. Their internal consistency was ascertained by the linear pH dependence of the emf of the cell (Pt|H2|pH standards in Z||NH4Cl bridge in Z|AgCl|Ag|Pt). Essential thermodynamic functions (standard emfs E° of cell and ionization constants of orthophthalic acid) hitherto unknown in the pertinent solvent Z had also to be determined from the emfs of the appropriate reversible cells. These pHPS and pHSS acquisitions enable the user to perform routine pHX measurements by the regular operational cell. A supplementary systematic search has been performed according to the method of Helmholtz transference cells both in N-methylacetamide and in its w = 0.50 mixture with water, to single out appropriate...

[1]  P. Mussini,et al.  Determination of primary and secondary standards and characterization of appropriate salt bridges for pH measurements in formamide. , 2004, Analytical chemistry.

[2]  G. S. Wilson,et al.  Measurement of pH. Definition, standards, and procedures (IUPAC Recommendations 2002) , 2002 .

[3]  P. Mussini,et al.  Medium effects, comparability and predictability of pH-standards in aqueous+organic solvent mixtures: behavior of the (ethylene carbonate+water) and (propylene carbonate+water) systems , 2001 .

[4]  P. Mussini,et al.  Ionization Constants of o-Phthalic Acid and Standard pH Values of Potassium Hydrogen Phthalate Buffer Solutions in Glycerol + Water Solvent Mixtures at Normal and Subzero Temperatures , 2000 .

[5]  P. Mussini,et al.  An alternative methodology for determining transport parameters of electrolytes in mixed solvents from concentration cells, without prior knowledge of activity coefficients , 2000 .

[6]  J. Barbosa,et al.  Assignment of pHS values of reference buffer solutions for standardization of potentiometric sensors in THF–water , 1999 .

[7]  P. Mussini,et al.  Recent advances in the electromotive force method for determining transference numbers of electrolytes and characterizing new salt bridges , 1998 .

[8]  P. Mussini,et al.  Reference value standards and primary standards for pH measurements in D2O and aqueousorganic solvent mixtures: New accessions and assessments (Technical Report) , 1997 .

[9]  A. G. González,et al.  Estimation of pH and autoprotolysis constants in mixtures of aliphatic amides with water: Medium effect on the 4-aminoazobenzene system. , 1993, Talanta.

[10]  P. Mussini,et al.  Reference value standards and primary standards for pH measurements in organic solvents and water + organic solvent mixtures of moderate to high permittivities , 1987 .

[11]  A. Covington,et al.  Criteria for standardization of pH measurements in organic solvents and water + organic solvent mixtures of moderate to high permittivities , 1985 .

[12]  J. Halle,et al.  Autoprotolysis Constants of Water–N-Methylacetamide Mixtures. A New Application of the Hammett Relationship to Acidity Constants , 1974 .

[13]  E. S. Amis,et al.  Conductance of sodium perchlorate in water-N-methylacetamide (NMA) solvent system , 1974 .

[14]  C. Holmes.  Relation between surface tension and dielectric constant , 1973 .

[15]  W. Hamer,et al.  Osmotic Coefficients and Mean Activity Coefficients of Uni‐univalent Electrolytes in Water at 25°C , 1972 .

[16]  D. Tassios,et al.  Effect of organic and inorganic salts on relative volatility of nonaqueous systems , 1971 .

[17]  T. Mussini,et al.  Standard potentials of the calcium amalgam electrode at various temperatures, with related thermodynamic functions , 1971 .

[18]  W. Gilkerson,et al.  The Dispersion of the Conductance of a Salt in Low Dielectric Solvents , 1965 .

[19]  H. Eckstrom,et al.  Solvents Having High Dielectric Constants. XV. Thermodynamic Properties of Solutions of Hydrochloric Acid in N-Methylacetamide by Electromotive Force Measurements1 , 1965 .

[20]  R. H. Graves,et al.  Solvents Having High Dielectric Constants. II. Solutions of Alkali Halides in N-Methylacetamide from 30 to 60°1a,b , 1955 .

[21]  E. Budge.  THE SPEED OF DECOMPOSITION OF HYDROGEN PEROXIDE IN THE PRESENCE OF HYDROCHLORIC ACID , 1932 .

[22]  B. B. Owen.  DIRECT MEASUREMENT OF THE PRIMARY, SECONDARY AND TOTAL MEDIUM EFFECTS OF ACETIC ACID , 1932 .

[23]  D. I. Hitchcock.  THE EXTRAPOLATION OF ELECTROMOTIVE FORCE MEASUREMENTS TO UNIT IONIC ACTIVITY , 1928 .