Download and follow the instructions in file “Experiment_Qualitative_Analysis_Instructions” below. These have been provided as a MS-word .docx file or as a PDF file. You will be directed to use a website to complete an online simulation of the qualitative analysis experiment.

Experiment_Qualitative_Analysis_Instructions.pdf

Online Lab Experiment Qualitative AnalysisA. General Background to Qualitative Analysis ExperimentQualitative analysis is a method used for identification of ions or compounds in a sample. In manycases, qualitative analysis will also involve the separation of ions or compounds in a mixture.Examples of qualitative tests would include ion precipitation reactions (solubility tests) orchemical reactivity tests. The separation of ions is easily achieved by taking advantage of theirsolubility properties.The goal of this lab is to use qualitative analysis to identify which cations are present in an“unknown” mixture containing one or more of the cations Ag+, Hg22+ and Pb2+ (known collectivelyas “Group I Cations”). In a lab simulation, you will use selective precipitation, which takesadvantage of the differing solubility of these ions in different conditions, to separate these ionsfrom the mixture and then confirm their presence or absence using selective chemical reactions.In the first part of the experiment you will use a qualitative analysis scheme with known solutionscontaining one or more of the group I cations to show how the ions behave and can be identified.In the second part, you will perform the same procedure with an assigned “unknown” and identifywhich of the group I cations is present or absent.B. Specific Background to this Experiment: Separation and Identification of Group ICations.Download the file “Qualitative Analysis Lab 364” from the assignment. This contains a portion ofa paper describing “The Chemistry and Qualitative Analysis of Cations: Group Separations andSeparation of Group I Cations”Read the sections titled: “Background Information”,”I, Separating Group I Cations fromGroup II, III and IV Cations” and “III. Group I Cations (Insoluble Chlorides)”These sections contain a specific background and explanation of the use of selective precipitationand confirmation reactions to separate and identify group I cations (Ag+, Hg22+ and Pb2+) in amixture of cations. Note that the separation procedure we will use in the online lab simulation isgenerally similar to that described in this paper. However, the details of the confirmations aredifferent and are described in the online lab simulation documentation (see below).Part C of these instructions contains information on how to use the online lab simulation.Part D of these instructions describes the experiments you should carry out.Part E contains instructions on postlab questions and how to submit your lab assignment.2C. Instructions for Online Qualitative Analysis Simulation.1. Go to the following website: http://web.mst.edu/~gbert/qual/qual.htmlThis site is called “Qualitative Analysis – Cations Group I” and contains an online simulationof a qualitative analysis experiment for group I cations. It was created by Prof. Gary Bertrandof the Department of Chemistry at Missouri University of Science and Technology(https://chem.mst.edu/) and we thank him for our use of this simulation.2. Toward the top of the page you will see heading for “Discussion”, “Flow Sheets”, “Operation”and “Check Unknown”:a) Click on “Discussion”. A new page will open that contains a description of the experimentprocedures and a suggested experiment to use known solutions. It is a good idea to printthis page if you can so that you can refer to it at any time.b) Click on “Operation” at any time to see instructions on how the various parts of the virtuallab simulation work.c) Click on “Flow Sheets” to see a representation of the steps in the qualitative analysisscheme used to separate and identify group I cations.d) Click on “Check Unknown” when you are ready to see if you have correctly identified thecations present and absent in your sample.3. Watch the powerpoint presentation found in the lab assignment. In this I will show you a runthrough of how the online QA lab simulation works.D. Experiments To Carry Out With Online Qualitative Analysis Simulation.General: Make notes and observations as you perform procedures with the simulation. It is a goodidea to note which test tube you put things into or decant from as you can’t label the tubes. Use to clear the simulation between experiments. If you get stuck, close your browserwindown and reopen the simulation by going to http://web.mst.edu/~gbert/qual/qual.htmlExperiment 1 – Analysis of known Group I Cations Separately: For your first experiment youcan carry out the “Suggested Experiment” described in the “Discussion” where you will analyzesolutions containing Ag+, Hg22+, and Pb2+ individually to see how they behave.Experiment 2 – Analysis of a known mixture of Group I Cations: For your second experiment,create a mixture of Ag+, Hg22+ and Pb2+ by placing one drop of each in a single test tube. To dothis select Ag (I) std from the “Samples” and place one drop of it in the first test tube. Repeat thisto add one drop of Hg (I) std and Pb (II) std into the same test tube. Once you have this mixture,carry out the procedure described in the flow sheet (see also powerpoint presentation) to separateand confirm the presence of all three ions in this mixture. Make careful notes of what you do andnote down what you observe at each step.3Experiment 3 – Analysis of a trial unknown: For your third experiment, select the “Trialunknown” from the samples and place 2 – 3 drops of it in the first test tube. This trial unknowncontains one or more the group I cations randomly selected by the simulation. Carry out the sameprocedure that you did before for a mixture of known group I cations (Experiment 2). Make carefulnotes of what you do and note down what you observe at each step. Use your observations, alongwith observations you made from experiment 2, to identify whether Ag+, Hg22+ and Pb2+ arepresent or absent in the trial unknown. When you are ready, click the “Check Unknown” and thenuse the appropriate buttons to select “Yes” for present and “No” for absent for each ion and thenclick “Check Answer” to see if you are correct.You can repeat this analysis of a trial unknown as many times as you like to practice. A new samplewill be created each time you select a trial unknown.Experiment 4 – Analysis of an assigned unknown: For your fourth experiment, you will analyzean assigned unknown that contains one or more the group I cations. I will assign you a specificassigned unknown (identified by a number from 101 – 999). Instructions for this will be found inthe main assignment instructions on Canvas. Make sure that you analyze the assigned unknownthat I provide you.TO MAKE SURE THAT THIS EXPERIMENT WORKS CORRECTLY, IT IS IMPORTANTTHAT YOU RESTART THE SIMULATION BY CLOSING THE WEBPAGE AND THENREOPENING IT BEFORE ANALYZING THE ASSIGNED UNKNOWN.Close your webpage, reopen a new page, and go to : http://web.mst.edu/~gbert/qual/qual.htmlSelect “Assigned Unknown” from the samples menu and type the number of your assignedunknown into the dialog box that opens. (To check that the simulation is working correctly, click“Check Unknown” and look to see if a box called “Prepare for print” appears below the optionsfor each ion. If it does you are OK. If it says “Check answer” then it still thinks you have a trialunknown and you need to restart the simulation.). Click “Operation” or “Flow Sheet” to see theappropriate instructions again.Now you are ready to analyze your assigned unknown. Carry out the same procedure that you didfor a mixture of known group I cations (Experiment 2). Make careful notes of what you do andnote down what you observe at each step. Use your observations, along with observations youmade from experiment 2, to identify whether Ag+, Hg22+ and Pb2+ are present or absent in yourassigned unknown. When you are ready click “Check Unknown”. Use the appropriate buttons toselect “Yes” for present and “No” for absent for each ion. Then click “Prepare for print”. Enteryour name in the dialog box that opens and click OK. A new page opens with a summary of youranswer. You can print this page from your web-browser. You will need an electronic copy of thissummary page for submission of your lab report. Use whatever options you have available onyour PC/Mac/other platform to make a digital copy: print it and take a picture, print it and scan theprint out, print to a PDF file if you have that capability, take a picture of your screen, take ascreenshot…. Name the file containing the summary page of the assigned unknown using theformat lastname_initial_QAlab_unknown4

E. Postlab Questions and Submission of Lab Assignment: When you have completed theexperiments in part D, including the assigned unknown, answer the postlab questions below. Youcan either write your answers using your MS-word editor (or equivalent), in the relevant spacesbelow OR print this page, write your answers by hand, and take a picture of your answers to submiton Canvas.WRITE YOUR NAME AND LAB SECTION HERE: _________________________

1. What property of group I cations like Ag+, Hg22+ an Pb2+ allows them to be separated fromgroup II and group III cations?

2. Write balanced chemical equations for the following reactions:a) AgCl (s) + NH3 (aq)b) Hg2Cl2 (s) + NH3 (aq)

3. For a solution containing at least one of the three cations involved in this experiment, answerthe following questions.

a) When HCl is added to the solution, a white precipitate forms. What cation(s) may bepresent in the solution?

b) The tube from part a) is centrifuged, decanted and hot water is added to the precipitate.After this is centrifuged, a white solid remains. What cations(s) may be present?

c) When the decanted liquid from part b) is cooled, a white precipitate forms. What cations(s)may be present.

d) When the white solid from part b) is treated with aqueous NH3 until basic, and thencentrifuged, there is no precipitate. When the decanted liquid is treated with HCl untilacidic and precipitate forms. What conclusions can be made about the presence or absenceof the cations in the original solution.

You may research the answers for Q 4 and Q 5 on the internet, in your textbook…5

4. Sodium sulfide (Na2S) and sodium sulfate (Na2SO4) are both colorless, odorless solutions.Imagine you have a beaker containing a colorless, odorless solution that you know is eithersodium sulfide or sodium sulfate. How could you use a chemical reaction to determine whichof the compounds is in the beaker? Use chemical equations to explain your answer.

5. Sodium chloride (NaCl) and potassium chloride (KCl) are both colorless, odorless solutions.Imagine you have a beaker containing a colorless, odorless solution that you know containsone of these two solutions. What test(s) could you use to determine which solution is in thebeaker.

Lab Assignment Submission: Save your answers to the postlab questions in a document witha filename based on your name e.g. lastname_initial_QAlab_postlabQ. Submit thisdocument, along with the print out from Experiment 4 (see Part D) by uploading into theassignment on Canvas. This must be done by deadline indicated in the assignment on Canvas.

The file “Qualitative_Analysis_Lab-364.pdf” that you will read for background information can be found below:

Qualitative_Analysis_Lab_364.pdf

A link to the online simulation website is present in the instructions file and can also be found here:

http://web.mst.edu/~gbert/qual/qual.html (Links to an external site.)

A powerpoint presentation containing a prelab demonstration of how to use the online simulation can be found below:

Using_Online_QA_Lab_Simulation_Demo.pptx

Carefully follow the instructions that describe how to perform the experiments and how to complete postlab questions.

IMPORTANT: TO FIND YOUR ASSIGNED UNKNOWN NUMBER, LOOK IN THE GRADES SECTION ON CANVAS. FIND AN ASSIGNMENT CALLED “QA Lab Unknown” AND YOU WILL SEE A SCORE REPRESENTING A NUMBER BETWEEN 101 AND 999. THIS THREE DIGIT NUMBER IS YOUR ASSIGNED UNKNOWN NUMBER.

MY UNKNOWN NUMBER IS 321

When you have completed this experiment, you will have two files. One file will your summary identifying an assigned unknown and the other will contain answers to postlab Q. Name these files as directed in the instructions and submit them using the Submit button on this page.

The deadline for this assignment is May 24th at 11:59 pm.

For the first link if it doesn’t open i provided the instruction under the link. The lab is not hard vary easy but i dont have time to do it.