How do I prepare the solutions for steps 1 and 2? MATERIALS Total ionic strength

Question

How do I prepare the solutions for steps 1 and 2?

MATERIALS Total ionic strength adjustment buffer (TISAB) Fluoride stock solution (500 ppm w/v) stir bar Two commercial mouthwashes (control and unknown) 10 mL volumetric flasks Fluoride ion selective electrode and 20-mL vials PROCEDURE 1. Prepare five 10.0 mL standard solutions (2 ppm, 5 ppm, 20 ppm, 50 ppm, and 100 ppm) adding 50 % v/v of the TISAB to each and then diluting to volume with DI water. Create a clear table in your notebook showing how you prepared your samples (and include room for a column to add the signal readings for each sample). Transfer these standards from your flasks to labeled 20-mL vials. 2. In a 10 mL volumetric flask, prepare a sample that contains 1.00 mL mouthwash and 50% v/v TISAB. The solution will be quite foamy, so take care not to add the TISAB and DI water too vigorously. You may also want to add the TISAB and some of the DI water prior to adding the mouthwash (be sure that you do not overshoot the mark, though). Mix well. It is okay if the solution is foamy after mixing. Repeat for the other mouthwash sample. Transfer these samples to labeled 20-mL vi

Explanation / Answer

use the C1V1=C2V2

you have been given a 500ppm stock solution

1)for 2 ppm

2ppm x 10ml=Xml x 500ppm

X=0.04ml

2)for 5 ppm

5ppm x 10ml=Xml x 500ppm

X=0.1ml

similarly do for the rest

so for example to prepare 2ppm solution you would have to take 0.04 ml of the stock given, add buffer and dilute to 10 ml in volumetric flask using distilled water.

make a table with columns volume of stock(find out from the C1V1=C2V2),volume of buffer(50%v/v of 10 ml is 5 ml),total volume(will be 10 for each)concentartion(given in your question),signal reading

2) here you juse have to use 1 ml of the stock mouthwash add 5 ml of buffer and dilute to 10 ml in the volumteric flask with distilled water

please do rate

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