Chemical Analysis by High Frequency Methods

Principles of High-Frequency Titrimetry

“…The steepest slope of the curve can be found by setting the second derivative of Equation 8 equal to zero and solving. The The k value at the mid-point where the capacitance is halfway between its extreme values, is found by setting Ci -/A ACP -Ctfc2 + W8C,C28 + u>8C2Ci8 /t8 + W2(Cl + C2)2 (11) so that as a result ^mid-point -Ol(C 1 -{-C2) (…”

“…This limit of accuracy served as a criterion for the evaluation of possible analytical procedures and standards. Since gravimetric determinations of sulfate as barium sulfate are unreliable because of coprecipitation (11), the choice of an acidimetric method and standard seemed obvious.…”

High-Frequency Titration: Theoretical and Practical Aspects

“…In cells where electrolyte concentration is less than about 0.1 M, R2 is usually negligible in comparison with Ri; its value varies from a few' tenths of an ohm to a few ohms, depending upon the design of the cell. Hence for such solutions, the equivalent circuit of Figure 2 is identical with that recently given elsewhere (3,22). This equivalent circuit does not include a term for the capacitance between the lead wires of the cell, and this must be corrected for before making calculations based upon the circuit.…”