The following data were obtained with a cadmium-selective solid-state electrode. The ionic strength of each solution was 0.30 M, and the reference electrode was a saturated calomel electrode. Determine the concentration of the unknown cadmium ion in the sample. [Cd2+], M 1.00x10-1 8.75x10-3 1.00x10-3 3.16x10-5 3.16x10-6 Unknown E, V -0.115 -0.150 -0.175 -0.213 -0.242 -0.200

The following data were obtained with a cadmium-selective solid-state electrode. The ionic strength of each solution was 0.30 M, and the reference electrode was a saturated calomel electrode. Determine the concentration of the unknown cadmium ion in the sample. [Cd2+], M 1.00x10-1 8.75x10-3 1.00x10-3 3.16x10-5 3.16x10-6 Unknown E, V -0.115 -0.150 -0.175 -0.213 -0.242 -0.200

Appl Of Ms Excel In Analytical Chemistry

2nd Edition

ISBN:9781285686691

Author:Crouch

Publisher:Crouch

Chapter11: Dynamic Electrochemistry

Section: Chapter Questions

Problem 5P

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A 0.2g sample of toothpaste containing fluoride was treated with 50 cm3 of a suitable buffer solution and diluted to 100 cm3. Using a fluoride ion-selective electrode, a 25.00 cm3 aliquot of this solution gave cell potentials of –155.3 mV before and –176.2 mV after spiking with 0.1 cm3 of a 0.5 mg/cm3 fluoride standard. Calculate the pF– corresponding to each cell potential and the percentage by weight of fluoride in the toothpaste.
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