As part of a soil analysis on a plot of land, a scientist wants to determine the ammonium content using gravimetric analysis with sodium tetraphenylborate, Na*B(C,H,). Unfortunately, the amount of potassium, which also precipitates with sodium tetraphenylborate, is non-negligible and must be accounted for in the analysis. Assume that all potassium in the soil is present as K,CO, and all ammonium is present as NH,Cl. A 5.045 g soil sample was dissolved to give 0.500 L of solution. A 125.0 mL aliquot was acidified and excess sodium tetraphenylborate was added to precipitate both K* and NH† ions completely. B(C,H,), + K* KB(C,H,),(s) Compound Formula mass KB(C,H,)4 358.33 g/mol B(C,H;), + NH NH, B(C,H;), (s) 337.27 g/mol NH,B(C,H;), K,CO3 138.21 g/mol The resulting precipitate amounted to 0.247 g. A new 250.0 mL aliquot of the NH,CI 53.492 g/mol original solution was made alkaline and heated to remove all of the NH as NH,. The resulting solution was then acidified, and excess sodium tetraphenylborate was added to give 0.115 g of precipitate. Find the mass percentages of NH,Cl and K,CO, in the original solid.

As part of a soil analysis on a plot of land, a scientist wants to determine the ammonium content using gravimetric analysis with sodium tetraphenylborate, NaB(C,H,). Unfortunately, the amount of potassium, which also precipitates with sodium tetraphenylborate, is non-negligible and must be accounted for in the analysis. Assume that all potassium in the soil is present as K,CO, and all ammonium is present as NH,Cl. A 5.045 g soil sample was dissolved to give 0.500 L of solution. A 125.0 mL aliquot was acidified and excess sodium tetraphenylborate was added to precipitate both K and NH† ions completely. B(C,H,), + K* KB(C,H,),(s) Compound Formula mass KB(C,H,)4 358.33 g/mol B(C,H;), + NH NH, B(C,H;), (s) 337.27 g/mol NH,B(C,H;), K,CO3 138.21 g/mol The resulting precipitate amounted to 0.247 g. A new 250.0 mL aliquot of the NH,CI 53.492 g/mol original solution was made alkaline and heated to remove all of the NH as NH,. The resulting solution was then acidified, and excess sodium tetraphenylborate was added to give 0.115 g of precipitate. Find the mass percentages of NH,Cl and K,CO, in the original solid.

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...

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