What indication in the "test tube test" (procedural step 9) will be given if Na3PO4 is the limiting reagent? What if BaCl2 is the limiting reagent? Explain why **Materials:**- Bunsen Burner- Ring stand- Wire mesh- 100 mL graduated cylinder (2)- 250 mL beakers (2)- 150 mL beaker- Test tubes (2)- Test tube rack- Glass stir rods (2)- Filtering funnel- Plastic transfer pipet- 250 mL Erlenmeyer flask**Note:** You will run two samples simultaneously. Perform the procedures for both samples. Obtain approximately the same volume of the same unknown samples for both trials.**Procedure:**1. Label the graduated cylinders with labeling tape. One will be used for the BaCl₂ solution and the other for the Na₃PO₄ solution.2. Obtain approximately 20 mL each of an unknown BaCl₂ and Na₃PO₄ solutions. Record the volumes (to the correct number of significant figures) in your notebook.3. In the 250 mL beaker, combine the 20 mL samples of BaCl₂ and Na₃PO₄ solutions and 100 mL of deionized water. Stir each trial solution for 3 minutes. When finished stirring, remove the stir rod from the beaker, cover with a watch glass, and allow the precipitate to settle.4. While the precipitate is settling, set up the ring stand with wire mesh, light the Bunsen burner, and adjust the flame to a blue flame (with no traces of yellow). Place one sample on the wire mesh and digest the precipitate for 15 minutes. **Do not let the mixture come to a boil!** The goal is to simply gently heat the reaction mixture. Remove the first sample from the ring stand after 15 minutes and digest the second sample for 15 minutes.5. After both reactions have finished digesting, heat about 100 mL of deionized water to 70-80 °C in the 150 mL beaker. This water will be used for washing the precipitate out of the beakers and for washing precipitate off of the stir rods.6. Set up the filtration apparatus. Obtain 2 sheets of fine porosity filter paper. Using **pencil**, write your initials and sample number on each paper. Fold each piece of filter paper into quarters. Then, open the filter as shown in **Figure 6.1**. Place the first filter paper in **Figure 6.1**: Opened filter paper to place into filter funnel.7. Stir your reaction vigorously before filtering. Decanting the liquid into the filter paper first will actually result in most of the solid flowing through the pores of the paper.8. Filter the first sample through the first filter paper. Transfer all of the precipitate by using a rubber policeman (rubber or Teflon™ spatula) and no more than three 5 mL aliquots of the warmed wash water. Be sure to collect as much of the precipitate as possible. When the filtration is complete, carefully remove the filter paper to a clean watch glass for drying in a safe place until the next laboratory period.9. Use the plastic transfer pipet to half-fill each of the two centrifuge tubes with the liquid filtrate. Only centrifuge the samples if necessary. Label the tubes I and II. Add 2 drops of BaCl₂ test reagent to tube I, and 2 drops of Na₃PO₄ test reagent to tube II. You should see an obvious precipitation reaction in only one of the tubes.10. Discard the filtrate (the liquid in the receiving flask) from the first sample into the liquid waste container and rinse the flask 3 times with deionized water. Use the second filter paper to filter the second sample in identical fashion to the first.11. Remove the filter paper from the funnel, unfold, and place on a watch glass. The sample should be placed in the oven for about 15 minutes to dry.12. Record the mass of the dried filter paper and precipitate.**Waste** All liquid waste can go in the aqueous waste container. Solid waste can be placed in the solid waste container.**Clean up** Rinse all glassware thoroughly with deionized water. Dry all glassware and return to the proper place.

To explain what happens at step 9.

Answered: What indication in the "test tube test"…

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...