2. The arsenic in a 1.203-g sample of a pesticide was converted to H3ASO4 by suitable treatment. The acid was then neutralized, and 40.00 mL of 0.05871 M AgNO3 was added to precipitate the arsenic quantitatively as Ag-AsO4. The excess Ag* in the filtrate and in the washings from the precipitate was titrated with 9.63 mL of 0.1000 M KSCN, and the reaction was Ag+ SCN → AgSCN(s). Find the percentage of As in the sample.

2. The arsenic in a 1.203-g sample of a pesticide was converted to H3ASO4 by suitable treatment. The acid was then neutralized, and 40.00 mL of 0.05871 M AgNO3 was added to precipitate the arsenic quantitatively as Ag-AsO4. The excess Ag* in the filtrate and in the washings from the precipitate was titrated with 9.63 mL of 0.1000 M KSCN, and the reaction was Ag+ SCN → AgSCN(s). Find the percentage of As in the sample.

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter13: Titrations In Analytical Chemistry

Section: Chapter Questions

Problem 13.22QAP

See similar textbooks

Similar questions

Twenty-five milliliters of a solution (d=1.107g/mL)containing 15.25% by mass of sulfuric acid is added to 50.0 mL of 2.45 M barium chloride. (a) What is the expected precipitate? (b) How many grams of precipitate are obtained? (c) What is the chloride concentration after precipitation is complete?
Iron (II) can be oxidized to iron (III) by dichromate ion, which is reduced to chromium (III) in acid solution. A 2.5000-g sample of iron ore is dissolved and the iron converted into iron(II). Exactly 19.17? ml. of 0.0100 M Na2Cr2O7 is required in the titration. What percentage of the ore sample was iron?
68. Aluminum ion may be precipitated from aqueous solution by addition of hydroxide ion, forming Al(OH)3. A large excess of hydroxide ion must not be added, however, because the precipitate of Al(OH)3 will redissolve as a soluble compound containing aluminum ions and hydroxide ions begins to form. How many grains of solid NaOH should be added to 10.0 mL of 0.250 M A1Cl3 to just precipitate all the aluminum?
A sample of solid calcium hydroxide, Ca(OH)2, is allowed to stand in water until a saturated solution is formed. A titration of 75.00 mL of this solution with 5.00102M HCl requires 36.6 mL of the acid to reach the end point. Ca(OH)2(aq)+2HCl(aq)CaCl2(aq)+2H2O(l) What is the molarity?
A chemist dissolves a 1.497-g sample of a type of metal (an alloy of Sn, Pb, Sb, and Cu) in nitric acid, and metastannic acid, H2SnO3, is precipitated. She heats the precipitate to drive off the water, which leaves 0.4909 g of tin(IV) oxide. What was the percentage of [in in the original sample?
Lead poisoning has been a hazard for centuries. Some scholars believe that the decline of the Roman Empire can be traced, in part, to high levels of lead in water from containers and pipes, and from wine that was stored in leadglazed containers. If we presume that the typical Roman water supply was saturated with lead carbonate, PbCO3 (Ksp = 7.4 1014), how much lead will a Roman ingest in a year if he or she drinks 1 L/day from the container?
When 85.0 mL of 0.250 M Ba(OH)2 solution is added to 85.00 mL of 0.250 M Al (NO3)3 solution, a white gelatinous precipitate of Al(OH)3; is formed. Assuming 100% yield, (a) what mass (in grams) of Al(OH)3 is formed? (b) what is the molarity of each of the ions Ba2+, OH-, Al3+, NO3- in the resulting solution?
The vanadium in a sample of ore is converted to VO2+. The VO2+ ion is subsequently titrated with MnO4 in acidic solution to form V(OH)4+ and manganese(II) ion. The unbalanced titration reaction is MnO4(aq)+VO2++(aq)+H2O(l)V(OH)4+(aq)+Mn2+(aq)+H+(aq) To titrate the solution, 26.45 mL of 0.02250 M MnO4 was required. If the mass percent of vanadium in the ore was 58.1 %, what was the mass of the ore sample? Hint: Balance the titration reaction by the oxidation states method.
An artificial fruit beverage contains 12.0 g of tartaric acid, H2C4H4O6, to achieve tartness. It is titrated with a basic solution that has a density of 1.045 g/cm3 and contains 5.00 mass percent KOH. What volume of the basic solution is required? (One mole of tartaric acid reacts with two moles of hydroxide ion.)
In order to determine the purity of ammonium sulfate, a sample with a mass of 0.850 g is dissolved in KOH. The equation for the reaction that takes place is NH4+(aq)+OH(aq)NH3(aq)+H2OThe ammonia liberated is distilled into a flask that contains 50.00 mL of 0.250 M HCI. Not all the HCI is consumed. The excess HCI reacts with 17.3 mL of 0.120 M NaOH. What is the mass percent of (NH4)2SO4 in the sample?