A solution contains some or all of the ions Cu2+, A3+, K*, Ca²+, Ba²+, Pb²+, and NH4*. The following tests were performed, in order, on the solution. 1. Addition of 6 M HCl produced no reaction. 2. Addition of H2S with 0.2 M HCl produced a black solid. 3. Addition of (NH4)2S produced a white solid. 4. Addition of (NH4)2HPO4 in NH3 produced no reaction. 5. The final supernatant when heated produced a purple flame. Identify which of these ions were present in the solution, which were absent, and for which ones no conclusions can be drawn.

A solution contains some or all of the ions Cu2+, A3+, K, Ca²+, Ba²+, Pb²+, and NH4. The following tests were performed, in order, on the solution. 1. Addition of 6 M HCl produced no reaction. 2. Addition of H2S with 0.2 M HCl produced a black solid. 3. Addition of (NH4)2S produced a white solid. 4. Addition of (NH4)2HPO4 in NH3 produced no reaction. 5. The final supernatant when heated produced a purple flame. Identify which of these ions were present in the solution, which were absent, and for which ones no conclusions can be drawn.

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 107E: What mass of NaCN must be added to 1 L of 0.010 M Mg(NO3)2 in order to produce the first trace of...

See similar textbooks

Similar questions

If KOH solution were used in Part B instead of Ba(OH), solution, then the chem A(OH)2 solution, then the chemical reaction would be: 2KOH(aq) + H2SO4(aq) → K2SO4(aq) + 2H2O(1) Looking at the products of this reaction, comment on any differences in conductivity that you would expect to observe when comparing the reaction above to the original reaction.
The dichromate ion Cr2 O722 and chromate ionCrO422 exist in equilibrium, like this:Cr2O722 (aq) 1 H2O ( l ) 2CrO422 (aq) 1 2H1 (aq)orange yellowa What would you see if you added dilute acid toa solution containing chromate ions?b How would you reverse the change?
A 1.219-g containing (NH4)2SO4, NH4NO3, and nonreactive substances was diluted to 200 mL in a volumetric flask. A 50.00-mL aliquot was made basic with strong alkali, and the liberated NH3 was distilled into 30.00-mL of 0.08421 M HCl. The excess HCl required 10.17 mL of 0.08802 M NaOH. A 25-mL aliquot of the sample was made alkaline after the addition of Devarda’s alloy, and the NO3- was reduced to NH3. The NH3 from both the NH4+ and NO3- was then distilled into 30.00 mL of the standard acid and back titrated with 14.16 mL of base. Calculate the percentage of (NH4)2SO4 and NH4NO3 in the sample.
1. A 0.973-g sample of canned tuna was analyzed by the Kjeldahl method. A volume of 21.15 mL of 0.1174 M HCl was required to titrate the liberated ammonia. Calculate the percentage of nitrogen in the sample 2. A 1.0325-g sample of a wheat flour was analyzed by the Kjeldahl procedure. The ammonia formed was distilled into 50.00 mL of 0.05045 M HCl. A 7.73-mL back-titration with 0.05017 M NaOH was required. Calculate the percentage of protein in the flour.
What mass of NaCN must be added to 1 L of 0.010 M Mg(NO3)2 in order to produce the first trace of Mg(OH)2?
What mass of solid AgBr is produced when 100.0 mL of 0.150 M AgNO3 is added to 20.0 mL of 1.00 M NaBr?
1. Why are Ce4+solutions never used for the titration of reductants in basic solutions?
How would you test a solution containing only Co2 and Fe3 ions?
4. You have a test tube containing a mixture of Ag+, Fe3+, and Ba2+. Make a diagram similar to Expt. 1 to separate the given mixture of cations. Include the correct reagents to be used to effectively isolate cations from each other.
For breakfast, the nihilistic Rick Sanchez ate 100 g of cereal mixed with 20 g of milk. A 1.500 g sample of the same cereal was analyzed using the Kjeldahl method, and the liberated NH3 was distilled into 50 mL of a 0.0227 M HCl solution, and back-titrated with 2.85 mL of 0.0112 M NaOH solution. A 1.100 g sample of milk was also analyzed, and the liberated NH3 was distilled into 55 mL of a 0.0234 M HCl solution, and back-titrated with a 3.10 mL of 0.0121 M NaOH. Use the values: MM N=14.07 g/mol. meat= 6.25 dairy= 6.38 cereal= 5.70 What is the % protein in the cereal sample? What is the % protein in the milk sample?
For breakfast, the nihilistic Rick Sanchez ate 100 g of cereal mixed with 20 g of milk. A 1.500 g sample of the same cereal was analyzed using the Kjeldahl method, and the liberated NH3 was distilled into 50 mL of a 0.0227 M HCl solution, and back-titrated with 2.85 mL of 0.0112 M NaOH solution. A 1.100 g sample of milk was also analyzed, and the liberated NH3 was distilled into 55 mL of a 0.0234 M HCl solution, and back-titrated with a 3.10 mL of 0.0121 M NaOH. Use the values: MM N=14.07 g/mol. meat= 6.25 dairy= 6.38 cereal= 5.70 1. What is the % protein in the cereal sample? a. 5.90% protein b. 10.21% protein c. 11.80% protein d. 20.42% protein 2. What is the % protein in the milk sample? a. 5.90% protein b. 10.21% protein c. 11.80% protein d. 20.42% protein 3. How many grams of protein did Rick consume over-all? a. 3.749 g b. 7.942 g c. 5.901 g d. 10.21 g
2.a. What conversion factor will enable you to calculate the number of moles of ClO– ions from the number of moles of S2O32− ions used in the titration? b. A 10.0-mL sample of aqueous NaOCl is treated with excess KI in an acidic solution. The quantity of iodine that is liberated is such that 28.02 mL of 0.0250 M Na2S2O3 solution must be added to cause the disappearance of the dark blue color due to the starch indicator. What is the molarity of the solution of NaOCl?