A sample of toothpaste was analyzed for its fluoride content by treating a 250 mg sample with an ionic strength buffer to extract F followed by dilution to 100.0 mL. The potential reading with a fluoride ISE was +150.3 mV. After addition of 10.0 mL of a 50.0 ppm F standard, the potential reading became +110.8 mV. Assuming a slope of –58.0 mV for the fluoride ISE, calculate the fluoride content of the toothpaste in %NaF. A 3.67 g sample of insecticide was decomposed in acid, any As* was reduced to As³* and diluted to 250.0 mL in a volumetric flask. A 5.00 mL aliquot was added to 125.0 mL of 0.0500 M KI buffered to pH 7. A coulometric titration was carried out with electrically-generated Is (3I → I5 + 2e) which oxidized As* to As* according to the reaction. As* + I; → 31 + As* The titration required 287 s at a constant current of 24.25 mA to reach the endpoint. Calculate the percentage of As2O3 (197.84 g/mol) in the insecticide.

A sample of toothpaste was analyzed for its fluoride content by treating a 250 mg sample with an ionic strength buffer to extract F followed by dilution to 100.0 mL. The potential reading with a fluoride ISE was +150.3 mV. After addition of 10.0 mL of a 50.0 ppm F standard, the potential reading became +110.8 mV. Assuming a slope of –58.0 mV for the fluoride ISE, calculate the fluoride content of the toothpaste in %NaF. A 3.67 g sample of insecticide was decomposed in acid, any As* was reduced to As³* and diluted to 250.0 mL in a volumetric flask. A 5.00 mL aliquot was added to 125.0 mL of 0.0500 M KI buffered to pH 7. A coulometric titration was carried out with electrically-generated Is (3I → I5 + 2e) which oxidized As* to As* according to the reaction. As* + I; → 31 + As* The titration required 287 s at a constant current of 24.25 mA to reach the endpoint. Calculate the percentage of As2O3 (197.84 g/mol) in the insecticide.

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

See similar textbooks

Similar questions

The student was supposed to measure the pH of a 0.1 M hydrochloric acid solution. For this purpose, he used a pH-meter and obtained the following results: 0.90, 0.93, 1.04, 1.02. Present the appropriate graphic and statistical elaboration of the performed analysis and confirm whether the applied pH-meter worked properly.
791#T>
Typo is A2z is supposed to be Ag2z.
Calculate the percentage purity of naproxen (FW 230.26) from the following data. 212.9 mg of naproxen was weighed and dissolved in a mixture of 25 ml of water and 75 ml methanol. It was titrated with 0.1024 M sodium hydroxide solution, using 1 ml of phenolphthalein solution as indicator. 8.08 mL of sodium hydroxide was required to neutralize the solution. Record your answer in decimal notation to 2 decimal places.
The molar conductivity of a saturated solution of thallium (1) bromide at 20°C is 2.158 x 102 Som¹ and that of pure water is 4.44 x 105 S m¹. The molar conductivity at infinite dilution is 138 S cm² mole-¹. Calculate the solubility of thallium (1) bromide in grams per liter.
9. Determine the ionic strength of a minimal growth medium that has the following composition: 0.150 M HEPES (a weak acid), 0.0500 M NH4NO3, 0.0140 M MgCl2, and 0.0240 M CaCl₂.
You are titrating 40.040.0 mL of 0.0100 M Sn2+Sn2+ in 1 M HCIHCI with 0.0500 M T13+T|3+ resulting in the formation of Sn4+Sn4+ and Tl+Tl+. A PtPt indicator electrode and a saturated Ag|AGCIAG|AgCl reference electrode are used to monitor the titration. Calculate the cell potential (EE) after each of the given volumes of the TI3+TI3+ titrant have been added. a. 1ml b. 4ml c.7.90ml d.8ml e.8.10ml f.13ml
please help me with this problem
Calculate solubility in the presence of a common ion. Calculate the solubility of PbCrO4 (a) in pure water and (b) in a solution in which [CrO42-] = 0.298 M. Solubility in pure water = 2- Solubility in 0.298 M CrO4²- = ΣΣ
A chemist mixes 10.0 mg of Ca(NO3)2 to a 100.0 mL sample of 0.010 M Na2C2O4 at 25 oC. Assume the volume of solution does not change. Given that for CaC2O4, Ksp = 2.7 x 10-9 at 25 oC, determine a) the value of Qsp (number and magnitude) of CaC2O4 dissolution and b) whether a precipitate should form.
Find the ionic strength of 1.0 mM Ca(ClO4)2.
Calculate the ionic strength of a saturated solution of La(IO3)3 with 0.010 M La(NO3)3. Kp = 1.0 x 10-I| 9.05 x 10- 6.05 x 10-2 4.68 x 10-3 1.21 x 10- 9.36 x 10-3