An unknown cadmium(II) solution was analyzed polarographically by the method of standard additions. A 26.00-mL sample of the unknown solution produced a diffusion current of 1.77 µA. Following addition of a 6.00-mL aliquot of 4.76 × 10-8 M Cd²+ standard solution to the unknown solution, a diffusion current of 5.26 µA was produced. Calculate the concentration of Cd²+ in the unknown solution. Concentration M

An unknown cadmium(II) solution was analyzed polarographically by the method of standard additions. A 26.00-mL sample of the unknown solution produced a diffusion current of 1.77 µA. Following addition of a 6.00-mL aliquot of 4.76 × 10-8 M Cd²+ standard solution to the unknown solution, a diffusion current of 5.26 µA was produced. Calculate the concentration of Cd²+ in the unknown solution. Concentration M

Appl Of Ms Excel In Analytical Chemistry

2nd Edition

ISBN:9781285686691

Author:Crouch

Publisher:Crouch

Chapter11: Dynamic Electrochemistry

Section: Chapter Questions

Problem 6P

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An unknown cadmium(II) solution was analyzed polarographically by the method of standard additions. A 25.00-mL sample of the unknown solution produced a diffusion current of 1.86 mA. Following addition of a 5.00-mL aliquot of 2.12x10^23 M Cd2+ standard solution to the unknown solution, a diffusion current of 5.27 mA was produced. Calculate the concentration of Cd2+ in the unknown solution.
The classical dissociation constant of propionic acid, C2H5CO2H, is 1.34 x10-5 moldm-3 at 250C and the limiting molar conductivities at zero concentration of hydrogen and propionate ions are 349.8 and 35.8 ohm-1 cm2 mol-1 respectively. Calculation of the resistivity of 0.100 M solution of propionic acid.
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An analyst wants to find out the active surface of his electrode before conducting his analyzes. To do this, he carried out a series of measurements by cyclic voltammetry (CV) using a 1 mM solution of K4Fe(CN)6 dissolved in 0.1M NaCl. He recorded the anodic peak intensity (ip) corresponding to the oxidation of Fe(II) to Fe(III) as a function of the scanning speed (v) of the CV (see table). What is the active surface of the electrode? Data: Fe diffusion coefficient (CN)64-, D = 6.67x10-6 cm2/s Randles-Sevcik equation ip = (2,69x105)n3/2ACD1/2v1/2 rate (v/s) ip (A) 5,00E-02 5,75E-05 1,00E-01 7,68E-05 2,00E-01 9,94E-05 5,00E-01 1,42E-04 1,00E+00 2,07E-04
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How long will it take to dissolve 2 mg of metal A (atomic weight 100) in a solution containing A2+ from a metal electrode with area of 1.5 cm2 at an overpotential of = 0.2 V? The exchange current density (j0) for A is 3x10-3 A/cm2, the temperature T=298 K and the symmetry factor =0.4.
1) Name the applications of glass electrodes in potentiometric measurements (please write correctly and concisely).
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