1. Calculate the concentration of ions in the following saturated solutions: (a) [1'] in Agl solution with [Ag'] = 9.1 x 10° M ; Ksp= 8.3 x 10" (b) [Al*] in Al(OH); solution with [OH] = 2.9 x 10° M ; Ksp = 1.8 x 10* 2. 2.4414 g sample containing KCI, K,S0, and inert materials was dissolved in sufficient water to give 250 ml of solution. A Mohr titration of a 50 mL aliquot required 41.36 mL of 0.05818 M AGNO,. A second 50ml aliquot was treated with 40 mL of 0.1083M NaB(C&Hs)4. The reaction is NaB(CaHs)4 + → KB(CGH;)4«s) + Na". The solid was filtered, redissolved in acetone, and titrated with K* 49.98mL of the AGNO; solution according to the reaction KB(C,Hs)a + Ag' + AgB(CGHS)4[s) + K*. Calculate the percentage of KCl and K;SO, in the sample. a. As a food chemist for a major potato chip company, you are responsible for determining the salt content of new potato chip products for the packaging label. The potato chips are seasoned with table salt, NaCl. You weigh out a handful of the chips (78.5 g), boil them in water to extract the salt, and then filter the boiled chips to remove the soggy chip pieces. You then analyze 100.0 mL of the chip filtrate for Cl' concentration using the Mohr method. First, you prepare a solution of AGNO3, and standardize it using 0.500 g KCl as the primary standard. Calculate for the concentration (in M) of the standard AGNO, solution if it takes 64.5 mL of the AGNO; titrant to reach the equivalence point of the reaction. Write the balance chemical reaction between the standard and the titrant. b. You then use the standardized AgNO, solution to analyze the chip filtrate in a Mohr reaction, finding that the solution yields a rusty brown precipitate when 48.8 ml of titrant is added. Calculate for the concentration (in M) of NaCl present in the potato chips filtrate. c. Draw the titration curve for the analysis of the chip filtrate after the addition of the following volumes of AGNO, solution: 15.0 ml, 24.4 ml, 48.8 ml, 49.5 mL and 50.0 ml. Kp for AgCl is 1.6х10 10 3. A0.5745g sample of an alloy containing principally Bismuth and Lead is dissolved in nitric acid and dilute to 250mL in a volumetric flask. A 50ml aliquot is withdrawn, the pH adjusted to 1.5 and the bismuth titrated with 30.26mL of 0.01024M EDTA. The pH of the solution is then increased to 5.0 and the lead titrated with 20.42mL of the same EDTA solution. Calculate the percentages of lead and bismuth in the alloy. 4. 25.0 mL of an unknown Ni2+ solution was treated with 25.00 ml of 0.05283 M N22EDTA. The pH of the solution was buffered to 5.5 and then back-titrated with 17.61 ml of 0.02299 M Zn2+. What was the unknown Ni2+ M?

1. Calculate the concentration of ions in the following saturated solutions: (a) [1'] in Agl solution with [Ag'] = 9.1 x 10° M ; Ksp= 8.3 x 10" (b) [Al] in Al(OH); solution with [OH] = 2.9 x 10° M ; Ksp = 1.8 x 10 2. 2.4414 g sample containing KCI, K,S0, and inert materials was dissolved in sufficient water to give 250 ml of solution. A Mohr titration of a 50 mL aliquot required 41.36 mL of 0.05818 M AGNO,. A second 50ml aliquot was treated with 40 mL of 0.1083M NaB(C&Hs)4. The reaction is NaB(CaHs)4 + → KB(CGH;)4«s) + Na". The solid was filtered, redissolved in acetone, and titrated with K* 49.98mL of the AGNO; solution according to the reaction KB(C,Hs)a + Ag' + AgB(CGHS)4[s) + K*. Calculate the percentage of KCl and K;SO, in the sample. a. As a food chemist for a major potato chip company, you are responsible for determining the salt content of new potato chip products for the packaging label. The potato chips are seasoned with table salt, NaCl. You weigh out a handful of the chips (78.5 g), boil them in water to extract the salt, and then filter the boiled chips to remove the soggy chip pieces. You then analyze 100.0 mL of the chip filtrate for Cl' concentration using the Mohr method. First, you prepare a solution of AGNO3, and standardize it using 0.500 g KCl as the primary standard. Calculate for the concentration (in M) of the standard AGNO, solution if it takes 64.5 mL of the AGNO; titrant to reach the equivalence point of the reaction. Write the balance chemical reaction between the standard and the titrant. b. You then use the standardized AgNO, solution to analyze the chip filtrate in a Mohr reaction, finding that the solution yields a rusty brown precipitate when 48.8 ml of titrant is added. Calculate for the concentration (in M) of NaCl present in the potato chips filtrate. c. Draw the titration curve for the analysis of the chip filtrate after the addition of the following volumes of AGNO, solution: 15.0 ml, 24.4 ml, 48.8 ml, 49.5 mL and 50.0 ml. Kp for AgCl is 1.6х10 10 3. A0.5745g sample of an alloy containing principally Bismuth and Lead is dissolved in nitric acid and dilute to 250mL in a volumetric flask. A 50ml aliquot is withdrawn, the pH adjusted to 1.5 and the bismuth titrated with 30.26mL of 0.01024M EDTA. The pH of the solution is then increased to 5.0 and the lead titrated with 20.42mL of the same EDTA solution. Calculate the percentages of lead and bismuth in the alloy. 4. 25.0 mL of an unknown Ni2+ solution was treated with 25.00 ml of 0.05283 M N22EDTA. The pH of the solution was buffered to 5.5 and then back-titrated with 17.61 ml of 0.02299 M Zn2+. What was the unknown Ni2+ M?

Chemistry by OpenStax (2015-05-04)

1st Edition

ISBN:9781938168390

Author:Klaus Theopold, Richard H Langley, Paul Flowers, William R. Robinson, Mark Blaser

Publisher:Klaus Theopold, Richard H Langley, Paul Flowers, William R. Robinson, Mark Blaser

Chapter15: Equilibria Of Other Reaction Classes

Section: Chapter Questions

Problem 10E: The Handbook of Chemistry and Physics (http://openstaxcollege.org/l/16Handbook) gives solubilities...

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