You are assigned an unknown solution that contains Group III cations. To -1 mL of this solution was added 6 M NH3 the solution was agitated to mix well, and a reddish-brown precipitate with a gelatinous solid clinging to the inner walls of the test tube was observed. The solution was centrifuged and the supernatant was tested for completeness of precipitation by adding an additional drop of 6 M NH3. No cloudiness was observed as the drop of reagent diffused through the solution. The supernatant was then carefully decanted into a clean test tube, labeled (1st solution), and saved for further testing later. The precipitate remaining in the test tube was washed with a small amount of water, centrifuged, and the wash decanted and discarded. To the precipitate was added about 10 drops of 6 M NAOH plus ~1 mL H20 and the test tube was vigorously agitated. The resulting suspension was centrifuged and the supernatant liquid was transferred to another clean test tube and clearly labeled (2nd solution). To the precipitate in the test tube several drops of 6 M HCI was added and mixed thoroughly dissolving the precipitate. Water was added to dilute the solution and the solution was mixed well to make it homogeneous. This was followed by the addition of a couple of drops of the reagent 0.1 M KSCN with mixing. The resulting solution turned blood red. Returning to the 2nd solution, 6 M HCI was added with agitation until the solution was acidic to litmus (blue to red). This was followed by adding a small excess of HCI. Two or three drops of the reagent aluminon was added plus -1 mL H20 and mixed well. The addition of 6 M NH3 followed until the solution was just basic to litmus. The solution was mixed well and upon standing for a few minutes a flocculent red precipitate was observed throughout an essentially clear solution. Analysis was continued by taking about one half of the decantate (solution one) and adding about 4-5 drops of thioacetamide solution and mixing. The solution was placed in a water bath at ~60°C under the fume hood for a few minutes. After a short period of time cloudiness with a grey to black precipitate was observed in the test tube. Based on the observations and information provided, identify the ion(s) present in your unknown solution. Options Fe^3+ Al^3+ Zn^2+

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...
icon
Related questions
Question
You are assigned an unknown solution that contains Group III cations. To -1 mL of this solution was added 6 M NH3 the solution was agitated to mix well, and a reddish-brown precipitate with a gelatinous solid clinging to the inner walls of the test tube was observed. The solution was centrifuged and the supernatant was tested for completeness of precipitation by adding an additional drop of 6 M NH3. No cloudiness was observed as the drop of reagent diffused through the solution. The supernatant was then carefully decanted into a clean test tube, labeled (1st solution), and saved for further testing later. The precipitate remaining in the test tube was washed with a small amount of water, centrifuged, and the wash decanted and discarded. To the precipitate was added about 10 drops of 6 M NAOH plus ~1 mL H20 and the test tube was vigorously agitated. The resulting suspension was centrifuged and the supernatant liquid was transferred to another clean test tube and clearly labeled (2nd solution). To the precipitate in the test tube several drops of 6 M HCI was added and mixed thoroughly dissolving the precipitate. Water was added to dilute the solution and the solution was mixed well to make it homogeneous. This was followed by the addition of a couple of drops of the reagent 0.1 M KSCN with mixing. The resulting solution turned blood red. Returning to the 2nd solution, 6 M HCI was added with agitation until the solution was acidic to litmus (blue to red). This was followed by adding a small excess of HCI. Two or three drops of the reagent aluminon was added plus -1 mL H20 and mixed well. The addition of 6 M NH3 followed until the solution was just basic to litmus. The solution was mixed well and upon standing for a few minutes a flocculent red precipitate was observed throughout an essentially clear solution. Analysis was continued by taking about one half of the decantate (solution one) and adding about 4-5 drops of thioacetamide solution and mixing. The solution was placed in a water bath at ~60°C under the fume hood for a few minutes. After a short period of time cloudiness with a grey to black precipitate was observed in the test tube. Based on the observations and information provided, identify the ion(s) present in your unknown solution. Options Fe^3+ Al^3+ Zn^2+
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps

Blurred answer
Knowledge Booster
Qualitative Analysis of Cations
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Chemistry
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Organic Chemistry
Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education
Chemistry: Principles and Reactions
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Elementary Principles of Chemical Processes, Bind…
Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY