Beer's Law Lab

Melinda Stauffacher


To find the absorbency of solutions to compare to anesthetics to help solve Aunt Elda's case.

Pre-Lab Questions

Before this lab, we had to know a little bit about anesthetics.

1) . Tell me about an experience that you have had with anesthesia (dentist/doctor/???) If you have never had the experience, do you foresee a future experience?

Yes, I had to have a root canal a few years ago and they gave me a lot of laughing gas before they gave me the numbing shot because I don't like needles so they wanted me to be loopy before the shot so I wouldn't squirm. I also had a few cavities so they gave me laughing gas for that. When I was hyped up on anesthesia I felt really weird like I was dreaming. My whole body felt tingly and the sounds around me were faded. There may come a point where I have to get my wisdom teeth out or undergo surgery and then, again, I would have to experience of anesthesia again.

2) What are characteristics (functions ) of an anesthesia that are desirable?

It relieves pain and numbs your body sometimes even knocks you out so you don't experience any pain or anything. It gives you a high so that you're out of things if you're having a painful procedure done or just to numb the pain for a little while.

3) What are characteristics (functions) of an anesthesia that are not desirable (dangerous)?

It causes side effects like nausea and pain. During the anesthesia, it causes acid to build up in your stomach making you feel sick. It can also cause memory loss making it difficult for patients. It's also flammable and toxic which can cause harm and damage to the body.


Local Anesthetics: Given by injection to numb parts of the body. Local anesthetics are usually given during surgery as well as dental procedures.

General Anesthetics: Put you to sleep. General anesthetics are given to you when you are undergoing a surgical or medical procedure that would be too painful to be awake during.

A common general anesthetic is N2O which was discovered at the end of the 18th century and is still being used during surgery.




-Graduated cylinder





-Anesthesia solution


1. Connect the colorimeter to the computer and opener Logger Pro and find the 1 lb. Beer's Law file

2. Insert your solution

3. Calibrate the colorimeter

4. Collect the data and be sure to hit the keep button

5. Discard the solution and get your next solution

6. Insert it into the colorimeter and be sure to collect and keep the data. DO NOT CALIBRATE again.

7. Repeat steps 5 and 6 until you have done all the solutions you have been assigned to do.

8. Examine the graph and compare the absorbency to the concentration.

9. Return all materials to their designated homes

How To Make a Solution

How to make a 10% solution.

First you start by taking your pipet that contains your solution. In our case the green water. You add it into a graduated cylinder to 1.00 mL. Then you take water and fill the graduated cylinder to 10.00 mL of water. So since we were doing 10% it was 1.00 mL of green solution and 9.00 mL of water to get an overall mix of 10.00 mL. You then repeat this for all 6 solutions but you do the first digit of the percent of the green solution then top it off at 10.00 mL with water. So you would do 2.00 mL solution to 8.00 mL's water. 3.00 mL's green solution to 7.00 mL's water. 4.00 mL's green solution to 6.00 mL's water. 5.00 mL's green solution to 5.00 mL's water. 6.00 mL's green solution to 4.00 mL's water.

Transparency Results Graph

Big image

Post Lab Questions

1) Was the concentration of Aunt Elda's anesthesia too strong? (how do you know)

No, the concentration of Aunt Elda's anesthesia was not too strong. 40% is too strong and that will kill you and Aunt Elda's concentration was 25%.

2) If yes, how did that cause her death? If no, do you have a hypothesis for the cause of her death?

Since the anesthesia wasn't too strong, we know this didn't cause her death. Depending on her surgery, there may have been other complications. Say it was brain surgery, maybe she bled out or maybe she went brain dead due to a tumor or something like that.

3) How did Beer's Law help you solve this case?

Beer's Law helps with the transparency of light and how it is absorbed so you are able to see concentrations and plot them. Therefore, without knowing the percent of the concentration of a solution, we were able to plot the unknown, which was Aunt Elda's percent concentration, and then find your percent after that.


After looking through the chart and graph above, we can conclude that the higher the green solution or anesthesia, the more absorbent it was. It's also proven that as light passes through, the amount of light is proportional to the intensity of the light.