Abstract

I conducted an experiment to calculate a reaction's change in enthalpy using heat of formation. The problem at hand was whether or not we could dissolve .2 g of a Magnesium ribbon in HCl. The results showed that if you do this, the temperature of the liquids in the calorimeter rose and the Magnesium ribbon took about 1-2 minutes to dissolve.

Safety Considerations

The safety considerations that I took while conducting the experiment was I wore safety glasses to prevent any liquids to get in my eyes. Also, I handled the materials very carefully so that I would not contaminate the experiment or me.

Materials

-Calorimeter

-1.0 M HCl

-Magnesium Ribbon

-Thermometer (Spark Temperature Probe)

-Graduated Cylinder

Procedure

-Put on safety glasses

-Cleaned out graduated cylinder and calorimeter with distilled water.

-Measured 50ml of HCl in a graduated cylinder.

-Poured the 50ml of HCl in a calorimeter.

-Measured .2g of a Mg Ribbon.

-Rolled the ribbon up in a loose ball.

-Placed ribbon ball in HCl and closed the calorimeter.

-Recorded the temperature every 15 seconds while occasionaly stirring the calorimeter until the ribbon fully dissolved.

-When reaction finished, I poured the waste into a waste bucket and cleaned out the materials and the lab area.

Evidence

Calorimeter- 29.29g

Mg Ribbon- .2g

0 sec.- 23.3 C

15 sec.- 28.3 C

30 sec.- 29.4 C

45 sec.- 36.9 C

1 min.- 39.8 C

1 min. 15 sec.- 40.7 C

1. 2HCl + Mg = MgCl2 + H2

2. Q = 3621.114 J (heat absorbed by HCl)

3. Q = 3.62 kJ (heat absorbed by HCl)

4. .008 mol of Mg used in reaction

5. 452.50 kJ/mol (enthalpy of reaction)

6. -466.75 kJ (theoretical heat of reaction)

7. 3.05 % error

Claim

I found that the temperature that a .2g Magnesium ribbon will completely dissolve into 1.0 M HCl is 40.7 C.

Explanation

In this experiment, I learned more about how to calculate the absorbing of heat in a reaction and how to apply the different numbers I got to the various equations I used. I can use these, or formulas, to solve various equations throughout various chemistry experiments involving chemical reactions.

I received a lot of feedback from Shivani, the person that looked at my paper. She explained all of the information that I should add. This included explaining more in depth about what biodiesel is, how and why it interests people, and the historical background of biodiesel production. She mainly explained the various things I could to do make my paper more appealing to scientists, like adding more scientific words and adding more statisical figures and numbers.

I plan on changing many things to my paper. For starters, I will add more scientifical words. After re-reading it, I could not agree with Shivani more. I did not really explain the production in depth as much as I could have. I will also fix my typos, add more statistics, go more in depth on the historical background, and more scientific information about biodiesel and its properties.

Research Question

How are pH and concentration correlated in strong vs. weak acids and bases?

Abstract

The experiment was mainly conducted to find out how pH and concentrations correlate in strong vs. weak acids and bases, as stated above. That is also the main problem being addressed in this experiment. To solve this question, we performed a serial dilution with acids and bases that were either weak or strong, which helped give us an answer to our question. In the experiment, my group found that with the lower amount of concentration of an acetic solution, the more the pH becomes. Also, the lower amount of concentration of a basic solution, the less the pH becomes. This is one of my group's main conclusions from this experiment.

Safety Considerations

Saftey glasses should be worn at all time to protect from the possibility of a solution getting into a person's eyes. Some chemicals are hazardous, so if they are not handled properly somebody may get hurt. Another way to prevent something bad from happening in the lab, the people doing the lab need to follow all instructions given.

Materials

-Microfuge tubes

-Spark pH probe

-pH paper

-Beakers

-Pipets

-Saftey Goggles

Procedure

1. Obtain .1M solutions of a strong acid (HCl), strong base (KOH), weak acid (acetic acid), and weak base (NH4OH).

2. Perform a serial dilution with each solution in microfuge tubes to get .1M, .01M, .001M, and .0001M solutions for each solution provided.

3. Label all tubes.

4. Determine the pH of each solution by adding one drop to a strip of pH paper.

5. Calculate the [H+], pOH, and [OH-] for each solution.

6. Identify the solution as strong or weak.

7. Create a line graph for each acid and each base.

8. Graph the concentration of the acid vs. [H+].

Evidence Collected

(Email)

Claim

The pH and concentration of a solution correlates with strong and weak acids and bases by having the less concentration of an acetic solution, the higher the pH gets, while the lower the concentration of a basic solution, the lower the pH becomes.

Scientific Explanation

Through this lab, I learned about the correlation between strong and weak acids and bases and the correlation involving the concentration and pH of each solution. It is a very important thing to learn because it can help us in the future when we learn more about serial dilutions. Overall, we can take many things from this experiment to use to build our knowledge of science and help our future in science.

Can we use colorimetry to prove Beer's laws?

The experiment was conducted to see how much red absorbance is absorbed into each of the six cuvettes. The problem being addressed was to find how much water it takes for a certain amount of stock solution to get a certain red absorbance. The methods we took were increasing the amount of water every time, which diluted the solution in the cuvette and measuring the various amounts to get a good reading of our solutions. The results we got were the higher amount of water and lower amount of stock solution, the lower amount of red absorbance. Our main conclusion was basically that the higher amount of water, the lower the red absorbancy will be.

In our experiment, we used safety goggles to prevent the solution from getting in our eyes. Another thing we did was kept it away from us so it would not get on our clothes and contaminate them. That also prevents it from spilling onto our skin and getting a chemical reaction.

In this experiment, we used a vile to combine the stock solution and water, safety goggles, colorimeter with Spark, and test tubes.

First, we took 25 mL of water and 3.121 g of CuSO4 to make the stock solution. Then we put a certain amount of solution and put it into a vile. Some viles needed more water, and the 6th one needed only water. With that, we put the tubes into the colorimeter to find the red absorbancy. Then we recorded our data, which ended the experiment.

We used .5M concentration of stock solution in every vile except for the last one, which was 0M. The volume of stock solution was the same number as the vile (Vile 1 is 1 mL, etc.) except for the 6th one, which was 0 mL. The volume of water for vile 1 was 4mL, vile 2 was 3mL, vile 3 was 2mL, vile 4 was 1mL, vile 5 was 0mL, and vile 6 was 5mL. the concentration of the final solution was, yet again, the same number as the vile except for 6, it was 0M. The volume of the solution was 5mL for every vile. Vile 1 had a red absorbancy of .516. Vile 2 had a red absorbancy of .941. Vile 3 had a red absorbancy of 1.245. Vile 4 had a red absorbancy of 1.856. Vile 5 had a red absorbancy of 2.223. Finally, vile 6 had a red absorbancy of 0.

We can use colorimetry to prove Beer's law because in this experiment, we did it many times and it worked. Beer's law is an accurate law.

We learned that in most cases, the more stock solution you use and the less water you use, the higher the red absorbancy will be. We also learned that you can actually use colorimetry to prove Beer's law because we found that that was true the more we tested our experiment.

In our experiment, we tested the concentration of a solution measuring transmittance percentage of the solution.

The experiment was conducted to find out how much light went through the solution. The problem being addressed was the issue about light going through the solution in a cuvette. We took solution and put it in the Spark to find what percentage of transmittance was in each solution. We did this to each vial until the transmittance became 100%. We found that the less of the concentration we used, the more transparent it was. Overall, we learned that you can use a colorimeter to find the concentration of a solution.

The safety concerns in this experiment are the concentration splashing into your eyes, so we wore safety goggles to prevent that from happening. Another safety concern is swallowing the concentration, so we just kept it away from our mouths.

The materials we used were liquid bluing solution, dilution well plate, plastic dropper, distilled water, 10 glass test tubes, Pasco Spark with a colorimeter, and glass cuvettes.

First, we labeled the test tubes 1-10. Next, we placed 5mL of liquid bluing in test tube #1. After that, we took 0.5 mL from test tube #1 and put it into test tube #2. We then added 4.5 distilled water to the 0.5 mL of original solution. Then we just repeated the dilution process until you can barely see the blue dye in the test tubes. We recorded the concentrations in a table on the worksheet.

The first test tube had 1x concentration and 0% transmittance. The second tube had .1x and still had 0% transmittance. The third one had .01x concentration and 9.7% transmittance. The fourth test .001x concentration and 66.3% transmittance. The fifth tube had .0001x concentration and 98.2% transmittance. The sixth tube had .00001x concentration and 100% transmittance. We stopped after that because the rest would have been 100% transmittance.

How much concentration will it take to get 100% transmittance? Well, for us it took until .00001x concentration to get 100% transmittance.

Overall, we found that it took 6 test tubes to get to 100% transmittance. The 6th tube ended up having .00001x concentration. The main thing is that it takes .00001x concentration to get 100% transmittance of liquid bluing solution.

The Standard Model has become an important tool for scientists because it basically explains everything in science. Subatomic particles are classified by their masses and by their interactions. Throughout the rest of my life, I can see scientists adding more particles to the Standard Model.