From the initial measurements you determine the electrode slope is -56.7 mV. You measure the initial potential of an unknown to be 84.5 mV. After the addition of 0.1027 M fluoride the potential drops to 39.9 mV. What is the molarity of fluoride in the original, undiluted, unknown? Answer is 3.97. How to derive?

From the initial measurements you determine the electrode slope is -56.7 mV. You measure the initial potential of an unknown to be 84.5 mV. After the addition of 0.1027 M fluoride the potential drops to 39.9 mV. What is the molarity of fluoride in the original, undiluted, unknown? Answer is 3.97. How to derive?

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter21: Potentiometry

Section: Chapter Questions

Problem 21.26QAP

See similar textbooks

Similar questions

Calculate the electrode potentials for the following systems: (a) Cr2O72-(5.00 10-3 M),Cr3+(2.50 10-2 M),H+ (0.100 M)|Pt (b) UO22+(0.100 M),U4+ (0.200 M),H+ (0.600 M)|Pt
Halide ions can he deposited at a silver anode, the reaction being Ag(s) + X- AgX(s) +e- Suppose that a cell was formed by immersing a silver anode in an analyte solution that was 0.0250 M Cl-,Br-, and I -ions and connecting the half-cell to a saturated calomel cathode via a salt bridge. (a) Which halide would form first and at what potential? Is the cell galvanic or electrolytic? (b) Could I- and Br- be separated quantitatively? (Take 1.00 l0-5 M as the criterion for quantitative removal of an ion.) If a separation is feasible, what range of cell potential could he used? (c) Repeat part (b) for I- and Cl-. (d) Repeat part (b) for Br- and Cl-.
Calculate the voltages of the following cells at 25°C and under the following conditions: (a) Zn|Zn2+(0.50M)Cd2+(0.020M)|Cd (b) Cu|Cu2+(0.0010M)H+(0.010M)|H2(1.00atm)|Pt
Calculate the voltages of the following cells at 25°C and under the following conditions: (a) Cu|Cu+(0.80M)Hg22+(0.10M)|Hg|Pt (b) Cr|Cr3+(0.615M)Ni2+(0.228M)|Ni
The measurement of pH using a glass electrode obeys the Nernst equation. The typical response of a pH meter at 25 00C is given by the equation where contains the potential of the reference electrode and all other potentials that arise in the cell that are not related to the hydrogen ion concentration. Assume that = 0.250 V and that a. What is the uncertainty in the values of pH and [H+] if the uncertainty in the measured potential is 1 m V ( 0.001 V)? b. To what precision must the potential be measured for the uncertainty in pH to be 0.02 pH unit?
The standard potential for the reduction of AgSCN is 0.0895 V. AgSCN(s)+eAg(s)+SCN(aq) Find another electrode potential to use together with the above value and calculate Kspfor AgSCN.