Question
Briefly explain whether each of the following procedural errors would result in a high, low, or an unchanged calculated mass of Ca 2+ ion in
Briefly explain whether each of the following procedural errors would result in a high, low, or an unchanged calculated mass of Ca2+ ion in the analyzed tablet. The Steps are at the bottom.
(a) A Student had difficulty decanting the supernatant solution from the test tubes in Step 9, causing him to transfer some of the solid along with the solution.
(b) When rinsing the binder material from the test tubes (step 24), a student observed small pieces of undissolved tablet in the solid at the bottom of the tubes.
(c) A student found that the litmus paper did not turn blue when tested with a drop of the solution in Step 11, then failed to add additional Na2CO3 solution and test the solution again before proceeding to Step 12.
(d) A student discarded the torn off filter paper corner, instead of placing it in the cone.
(e) After labeling the filter paper, a student left wet fingerprints on the paper when transferring it to the balance to determine its mass.
(f) A student failed to determine the mass of the filter paper prior to filtering the CaCO3 in Part III(Filtering and Drying the CaCO3). Realizing the importance of this mass, he selected a new piece of filter paper and used its mass in his calculations.
Steps are Below:
Step 9: Decant the supernatant solution from both test tubes into a clean 150 ml beaker. Use a pasteur pipet or medicine dropper to add 25 drops of 2.0M HCl solution to the solid in each test tube. If bubbling occurs when you add the last drops, add 10 additional drops of HCl solution. Centrifuge the mixtures in both test tubes again, and carefully decant the supernatant liquid from both tubes into the beaker containing the other supernates.
Step 24: Add 1-2mL of tap water to the solids in your test tubes and your original reaction beaker. Agitate the mixtures and transfer into the container and labeled "Discared Tablet Binder."
Step 11: Transfered a drop of the supernatant solution to the litmus paper, if it doesnt turn blue obtain 5 more ML of 1.0M Na2CO3 solution, add it to the mixture and stir. Allow the mixture to stand 5 min, then repeat the litmus paper test.
Step 12: Use an analytical balance to determine the mass of the filter paper to the nearest 0.001 g.
Step by Step Solution
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