Chicago River Lab

3 Things I Learned in this Lab:

1. Chicago has 37 moveable bridges. 
2. The Michigan Avenue bridge is a double-lear, double deck bascule trunnion bridge. 
3. Chicago bridges are painted red to recreate the original paint color, which was red lead paint (to prevent rusting) mixed with black powder (to tone down the red). 

2 Things I Found Surprising in this Lab: 

1. I was surprised that the Chicago River was so clean according to all of our tests; I've grown up in Chicago and have been told by my whole family to never swim in the river or even go too close to it for fear of pollution. However, the tests we performed in this lab disproved their theories of its severe pollution. 
2. I was surprised that the bridge requires so little energy to be moved. In the museum, a sign said that the amount of energy needed to lift the bridge is the amount of energy in a 1950s Volkswagen Bug motor. 

1 Question I Have After This Lab:

1. Who/what else was affected by the River's pollution before the flow was reversed? Because of the amount of pollution and untreated sewage that went into Lake Michigan, which is so large and connects so many places, what other places or people were affected?

The test I did was of the Chicago River's pH. This test measures the concentration of hydrogen atoms and the acidity of a fluid. This is important because too much or too little acid in a river can be dangerous for the environment in and around the river. We took a sample of river water, placed a pH testing fluid in, waited for the water to change color, and then matched that color to one on a chart to see what the pH was. 

Based off of the Q values found in class, we can classify the river's quality as excellent. However, we were so close to the lake that our results might have been tainted by the low percentage of actual river water. However, this could be improved if fewer things are put into the river; for example, runoff from chemicals often gets into the river and pollutes it. I personally can work to reduce the number of chemicals I use in my life (in hair products, soap, food, etc.) to cut down on the number of chemicals that could potentially enter the environment. 

Lab 14: Titration

Titration setup

Analyte at equivalence point

For our procedure, we used NaOH, vinegar, and phenolphthalein to identify the percent ionization of vinegar. We first obtained a burette and primed it with NaOH to clean and prepare it. Next, we filled the burette to 50 milliliters of NaOH. We then filled an Erlenmeyer flask with 7.0 milliliters of vinegar, 20 milliliters of water, and 4 drops of phenolphthalein. We then measured drops of NaOH into the Erlenmeyer flask until the solution turned barely pink, which was the point of equivalence of the vinegar. We did this twice and measured that it took 22.30 milliliters to turn the substance pink the first time and  22.10 milliliters the second time.

The percent ionization of the vinegar is .489%. This is so low because vinegar only has 1 ionizable proton (Hydrogen), which makes the possibility of it ionizing very, very small.

Lab 17: Calories in Food

In this lab, we measured the Calories in certain food by burning the food and then measuring how much heat the food let off by boiling water. The amount of heat that the water gained was the amount of water that the food lost, which allowed us to then calculate how many calories the food had.

 

Lab 16: Specific Heat of a Metal

Our setup

Lab 16: Specific Heat of a Metal

For this lab, we were provided with an unidentified metal. To identify this metal, we heated it in a beaker of water and used the changes in the water temperature to identify the heat that the water gained and use the opposite as the energy that the metal lost to find the metal's specific heat. Once we calculated how much energy the metal lost, we found its mass and its temperature change. The specific heat we calculated was 0.17 g/jC, which would make our metal iron.

Lab 15: Evaporation and Intermolecular Attractions

    

Substance	Initial Temperature  (Degrees Celsius)	Final Temperature (Degrees Celsius)	Change In Temperature (Degrees Celsius)
Methanol	21.1	6.5	-14.6
Ethanol	19.8	11.3	-8.5
n-Butanol	20.9	18.7	-2.2
Glycerin	21.3	24.4	+3.1
Water	20.7	16.7	-4.0

2) The substance with the largest difference in temperature was methanol. This was because methanol has the fewest places for intermolecular hydrogen bonding to occur, so it was easier to break apart and evaporate, causing the greatest temperature change.

3) Methanol and ethanol have similar molecular masses but had different evaporations. Methanol had a temperature change of -14.6 degrees Celsius and ethanol had a temperature change of -8.5 degrees Celsius. This is because methanol has fewer possible intermolecular hydrogen bonds, so it's an easier substance to break apart than ethanol, which has more places for possible intermolecular hydrogen bonds to occur.

4) All of the compounds in these substances are formed through hydrogen bonds and these specific molecules bond together through bonds between oxygen and hydrogen atoms. Therefore, the more oxygen and hydrogen atoms a molecule of these substances has, the less likely one of these substances is to break apart. For example, methanol has the fewest number of hydrogen and oxygen atoms and n-Butanol has the most, which corresponds to the fact that methanol evaporated the fastest and n-Butanol the slowest.

Lab 11: Flame Test Lab

In this experiment, we used a bunsen burner to ignite different chemical solutions that had been soaking onto a wooden splint. The ignition of these solutions created many different colored flames which we observed.

For the last part of the lab, we identified the unknown substances based off of the data we had collected about the known substances. For unknown solution one we identified it as Strontium Chloride. When we burned the substance, it gave off very red light. We knew that it was either SrCl2 or LiCl because both of those gave off red light; however, LiCl gave off orange light in addition to red light and the unknown substance gave off solely red light, which allowed us to determine the true identity of the substance. Unknown substance two gave off a purple light. The only solution that gave off a purple light in our experiment was Potassium Chloride, so we knew that the unknown substance had to be Potassium Chloride, or KCl.

 

Lab 12: Electron Configuration Battleship

The hardest thing about playing this game was starting it off; I was still confused about how exactly to name the electrons and I was intimidated to have to state the configurations in a pressuring game scenario. However, I used my reference packet and labeled periodic table and it proved to be easy enough to name them once I got started. Through this activity, I became much more confident in my abilities to identify an electron through off of its configuration.

My battleship configuration is on the bottom and my partner's is on the top. My partner sunk two of my ships (the ones with green xs) and I sunk two of his, including his battleship (the ones highlighted in green on top).