I am not sure how to start this. You are given a 200% solution of a compound. You must dilute and construct a calibration curve to interpret concentration of compound in unknown samples. Show the steps needed to perform a two-fold serial dilution through 5 tubes.

How in the world do you make a 200% solution.

Not sure that is what the question asks from my instructor. I am totally confused.

To perform a two-fold serial dilution through 5 tubes, you will need to dilute the 200% solution multiple times. Here are the steps:

1. Start by labeling your 5 tubes from 1 to 5. These tubes will represent the dilution series.

2. For the first tube (Tube 1), you will begin by adding a known volume of the 200% solution. Let's assume the initial volume is 1 mL.

3. In Tube 2, you will dilute the contents of Tube 1 by a factor of 2. To do this, transfer 1 mL from Tube 1 into Tube 2, and then add 1 mL of a suitable diluent (such as water).

4. Repeat step 3 for Tubes 3, 4, and 5. Each time, take 1 mL from the previous tube and transfer it to the next, then add 1 mL of diluent.

5. Now, you have a dilution series with Tube 1 being the least dilute and Tube 5 being the most dilute. The dilution factors from Tube 1 to Tube 5 will be 1, 2, 4, 8, and 16, respectively.

6. Prepare a calibration curve by measuring the concentration of the compound in each tube. You can use appropriate analytical techniques like spectrophotometry or chromatography to determine the compound's concentration in each tube.

7. Plot a graph with the dilution factor (x-axis) against the compound's concentration (y-axis) for the five tubes. This will result in a calibration curve.

8. Once you have the calibration curve, you can use it to interpret the concentration of the compound in unknown samples. Simply measure the absorbance or response of an unknown sample and find the corresponding concentration on the calibration curve.

By following these steps, you will be able to perform a two-fold serial dilution and construct a calibration curve to interpret the concentration of the compound in unknown samples.