BEER'S LAW

In this lab, we demonstrated Beer's Law, which states that the more concentrated a solution is, the darker it is, since it has more of the solute dissolved in the solvent.

Purpose: To determine the concentration of unknown nickel (II) sulfate solutions as determined by the absorbance measured by the colorimeter hooked up to the mac book through logger pro.

Materials:

-Nickel nitrate solution (0.4 M)

-Test tubes
-Test Tube Rack
-2 pipets
-Cuvette
-Vernier Colorimeter
-LoggerPro program
-Distilled Water



Procedure:

1.) Goggle time! Put those goggles on people, Caution when using NiSO4 solutions.

2.) Add distilled water to a cuvette and insert it in the colorimeter, then set the colorimeter to no light and calibrate the unit.

 ( Mr. Ludwig-Why dont we want it to be on green if the solution is green?
Kandace-We wont see anything!)<-- See i was here for that conversation!!! :)
2) Set the colorimeter to red light not green!

3) To begin with add 2 mL of  nickel nitrate solution to a test tube. To reduce add 8 mL of distilled water to the test tube. Stir thoroughly to make the solution concentrated. Pour solution into a cuvette. Insert cuvette into the colorimeter and record the absorbance.

4) Next, add 4 mL of the nickel nitrate solution to a test tube, this time add 6 mL of distilled water to the test tube and of course stir thorough it properly. Pour this concentrated solution into a cuvette as well and insert the cuvette into the colorimeter and record the absorbance.

5) Continuing on, add yet another 6 mL of nickel nitrate solution to a test tube. After that add 4 mL of distilled water to the test tube and stir thoroughly. Pour the solution into a cuvette. Insert the cuvette into the colorimeter and record the absorbance.

6) Add 8 mL of the nickel nitrate solution to a test tube. Add 2 mL of distilled water to the test tube. Stir thoroughly. Pour solution into a cuvette. Insert cuvette into the colorimeter and record the absorbance.

7) Add the pure 0.4 M nickel nitrate solution to a cuvette. Insert cuvette into the colorimeter and record the absorbance.
8) Set a line of best fit that runs through the middle of your data to have an average of the data plotted.
9) Add the 1st solution with one of the unknown concentrations to a cuvette. Insert cuvette into the colorimeter and use the line of best fit to determine its concentration.

10) Add the 2nd solution with one of the unknown concentrations to a cuvette. Insert this cuvette into the colorimeter and use the line of best fit to determine its concentration.

11) Add the 3rd solution with an unknown concentration to a cuvette. Insert the cuvette into the colorimeter as well and use the line of best fit to determine its average concentration level.



Steven's Groups Data! Thank you Steven!!
Absorbance of the solutions are:

Unknown 1: .186

Unknown 2: .551

Unknown 3: .367

Concentrations of the solutions are:

Unknown 1: .155 M

Unknown 2: .365 M

Unknown 3: .26 M

Conclusion:

Although I did not actually do this lab I did have to research a little to actually understand what was going on within this experiment. And thanks to Steven and his group I was able to get the data they had collected while conducting this experiment. In conducting this experiment it became aparent that in order to determine the concentrations of the given solutions, each of the group's had to use Beer's Law acurately. By using Beer's Law each group was able to compare the absorbancies of each of the solutions.