QUESTION 1 Place the following steps in the order (1 to 6) you will perform them

Question

QUESTION 1

Place the following steps in the order (1 to 6) you will perform them when conducting this experiment and analyzing your results.

- Using the volumes of iron and ligand solutions determined from the graph, and the concentrations of the solutions (taking into account any dilutions that were performed), find the number of moles of iron and ligand at the ideal ratio. Divide the number of moles of ligand by the number of moles of iron to find n, the number of ligands per iron atom.

- Given the total volume of solution in the cuvette, the constant volume of hydroxylamine solution, and the volume of iron at the ideal ligand/iron ratio, find the volume of ligand at the ideal ratio.

- Record the concentrations listed on the bottles for all reagents in your laboratory notebook.

- Conduct tissue culture plate analysis. If no "break" is observed in the color of the wells, dilute the stock solution appropriately and repeat the experiment.   

- Determine the conversion factor between tissue culture plate and cuvette. Convert the drops of each component in the wells of the plate into milliliters to use in the cuvette.

- Collect absorbance spectra for the solutions in the cuvettes. Graph absorbance vs volume of iron, and determine the volume of iron at the intersection of the two lines.

QUESTION 2

A solution is made by dissolving 1.00 g of the ligand ethylenediamine (C2H8N2) in enough water to make to make 1.00 L of solution. Determine the concentration of the resulting solution.

QUESTION 3

A 0.00307 M solution of a ligand must be diluted by a factor of five. This is done by measuring 20.00 mL of the original solution into a 100.00 mL volumetric flaskand adding enough water to bring the total solution volume to the mark on the volumetric flask. What is the ligand concentration in the resulting solution?

QUESTION 4

In order to perform an analysis, three solutions are mixed in a cuvette. There are 0.47 mL of a ligand solution, 0.54 mL of a hydroxylamine solution, and 1.03 mL of an iron solution. If the concentration of the ligand stock solution is 0.125 M, what is the concentration of the ligand in the cuvette?

QUESTION 5

In this lab, you will carry out dilutions using a dropper to get qualitative information about metal/ligand ratios. Two drops of hydroxylamine solution are placed in a 0.50-mL well. Then eight drops of ligand solution, and 4 drops of 5 mg L-1 iron solution are added. How many nanomoles of iron are in the well?

Useful conversion factors:

There are about 20 drops in 1 mL.

1 nanomole = 1x10-9 moles

QUESTION 6

A tissue culture plate experiment is done by adding 3 drops of hydroxylamine solution, 4 drops of ligand solution, and 8 drops of iron solution to a well in the plate. If you want to repeat the experiment on a larger scale, what is the conversion factor from plate to cuvette assuming that you need to make 2.2 mL of total solution volume?

QUESTION 7

A properly done graph of your results will look something like this. The ideal ratio of ligand to iron can be determined from the volume of iron solution where the two lines intersect, that is, where they have the same x and y values. The volume of iron is on the x axis, and absorbance is on the y axis. The x value can be determined by setting the equations of the lines equal to each other, and solving for x. What is the volume of iron in mL at the ideal ratio for the results pictured here?

Explanation / Answer

following the the steps in the order (1 to 6) you will perform them when conducting the experiment and analyzing the results-

1. Collect absorbance spectra for the solutions in the cuvettes. Graph absorbance vs volume of iron, and determine the volume of iron at the intersection of the two lines.

2. Given the total volume of solution in the cuvette, the constant volume of hydroxylamine solution, and the volume of iron at the ideal ligand/iron ratio, find the volume of ligand at the ideal ratio.

3. Record the concentrations listed on the bottles for all reagents in your laboratory notebook.

4. Using the volumes of iron and ligand solutions determined from the graph, and the concentrations of the solutions (taking into account any dilutions that were performed), find the number of moles of iron and ligand at the ideal ratio. Divide the number of moles of ligand by the number of moles of iron to find n, the number of ligands per iron atom.

5. Determine the conversion factor between tissue culture plate and cuvette. Convert the drops of each component in the wells of the plate into milliliters to use in the cuvette.

6. Conduct tissue culture plate analysis. If no "break" is observed in the color of the wells, dilute the stock solution appropriately and repeat the experiment.

2. Mass of ethylenediamine = 1.00 g

Molar mass of ethylenediamine = 60.10 g·mol1

Moles of ethylenediamine = 1.00 / 60.10

= 0.0166 moles

Volume of solution = 1.0 L

Concentration of solution = 0.0166 / 1.0

= 0.0166 M

3. Initial concentration of ligand solution, M1 = 0.00307 M

Initial volume of ligand solution, V1 = 20.0 mL

Final volume of ligand solution, V2 = 100.0 mL

Let the final concentration of ligand solution be M2

Using M1V1 = M2v2

0.00307 * 20 = M2 * 100

M2 = 0.00307 * 20 / 100

M2 = 6.14 x 10^-4 M

So, the ligand concentration in the resulting solution = 6.14 x 10^- 4 M

4. Concentration of the ligand stock solution = 0.125 M

Initial volume of ligand solution = 0.47 mL

mmoles of ligand = 0.125 * 0.47

= 0.05875 mmoles

Total volume of resulting solution = 0.47 + 0.54 + 1.03

= 2.04 mL

Concentration of the ligand in the cuvette = 0.05875 / 2.04

= 0.0287 M

Related Questions

Navigate

• Browse (All)
• Browse Q
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.