nguyenjhhs's posterous

Research Question: What is the enthalpy of the reaction between Mg and HCl?

Abstract: 

 This lab was conducted to help teach us how to make a reaction in a controlled safe environment. It's basically figuring out the enthalpy of a reaction. By measuring the heat produced or absorbed, enthalpy can easily be determined. This lab was quick and easy to do. One of the problems was deciding when the reaction was completed. To solve that you would have to notice that the final temperature stayed constant then you would know if the reaction finished. 

Safety Considerations:

• Wear SAFETY glasses at all times. 
• This reaction can give off irritating vapors so work at arm's distance
• Keep calorimeter lids on at all times
• Wash off immediately if skin comes in contact with HCl

Materials:

• Magnesium Ribbon
• 1.0M HCl
• Styrofoam Calorimeter
• Thermometer
• Gloves if needed

Procedure:

1. Gather up equipment & put on safety glasses.
2. Measure out 50.0ml of 1.0m HCl and pour into a pre-weighed calorimeter.
3. Record the mass of the calorimeter + HCl
4. Record the starting temperature of the HCl
5. Measure out no more than 0.2g of magnesium ribbon. Record the actual mass.
6. Roll up the Mg ribbon into a losse ball. When ready, place the Mg into the HCl. Quickly place BOTH lids on the calorimeter and slide the thermometer probe into the reaction mixture.
7. Record the temperature every 15 seconds, until the reaction is complete ( you'll be able to hear the gas being given off when it's reacting)
8. When the reaction is complete, record the final temperature.
9. Rinse off the thermometer probe and pour the reaction mixture into a waste container, with an equal volume of tap water to "neutralize" any remaining acid.
10. Clean off your lab table, put away equipment, and return to your seat.

Evidence Collected:

Mass of Calorimeter + HCl = 78.93g

Calculations:

1. Balanced Equation: Mg + 2HCl →H2 + MgCl2
2. Q= 2728.7 j
3. 2.728 Kj
4. 5.487 x 10^-13 mol HCl
5. -497.1751412
6. 7.6%

Claim: Calculation number 5 is the enthalpy of the reaction between Mg and HCl.

Scientific Explaination: I learned how to determine the enthalpy of a reaction in a safe controlled environment.

Summary:The feedback i have recieved was what i kind of predicted. I had some positive and negative feedback. The person liked my title and cover alot. Much of my my concepts are good but a little disconnected. In my paper i could easily confuse my reader.

Things to Change

1. Rearrange some paragraphs
2. Cite more of my sources to the text in my paper
3. Explain more of my concepts
4. Talk bout my title & graphics
5. Reintroduce words in the text early for the reader to read

The person that sent me feedback was Dr. Alexis Campbell. Her position is Biochemistry/Biophysics & Molc Biol-AGLS

Question: Can we verify Beer's Law by determining the concentration of an unknown solution?

Abstract:

This experiment was conducted in order to learn about and understand the concepts of Beer's Law through concentration and absorbancy. The problem addressed had to do with verifying Beer's Law. In order to do so, the colorimetry technique was utilized and CuSO4 was used as our unknown solution. The major result found was that test tube #5 had the highest rate of Red absorbancy with the highest concentration of solution of CuSO4. So you will notice throughout the experiment that the more concentration of CuSO4 you use the greater chance you'll have a higher rate of Red Absorbancy.

Safety Considerations:

• Wash Hands before and after the lab
• Wear Safety Glasses 8)
• Make space for materials to eliminate accidents during the lab

Materials:

• Safety Glasses
• Pasco Spark System with Colorimeter
• 6 Glass Cuvettes
  
• 6 Test Tubes
• Distiled Water
• Graduated Cylinder
• Plastic Dropper
• Lab Scale
• Pipettes
• 25 ml volumetric flask
• Copper (II) Sulfate solution

Procedure:

• Create & fill a data table
• Label Test tubes
• Put 25ml of distilled water into the Flask
• Make the stock solution by taking 3.121g of CuSO4 and dumping it into the 25ml Flask
• Next shake up the flask to dissolve and mix the solution with the distilled water. Make sure to put a cork in it.
• Now follow the data on your table/chart to make the dilutions

(Dilution Process)

• Using pipettes place 1ml of solution and 4ml of distilled water into test tube 1
• Place 2ml of solution & 3ml of water into test tube 2
• Place 3ml of solution & 2ml of water into test tube 3
• Place 4ml of solution & 1ml of water into test tube 4
• Place 5ml of solution & no amounts of water into test tube 5
• Lastly place 5ml of water into test tube 6

(PASCO SPARK SYSTEM)

• Hook up the system and cords correctly
• Turn on & Calibrate the colorimeter
• Now take the solutions in the test tubes and pour them into glass cuvettes
• Use the system & Analyze the Red Absorbance of each solution by placing it into the colorimeter
• Record all of your results!
• Then create a line graph using Excel using the concentration of Final solution and Red Absorbance data from your table you made
• Now clean up and return all lab equipment to their original places and don't forget to wash your hands ;)

Evidence Collected:

(download)

Click here to download:

beer-s-law-lab-uhqgauhyqoEmtyCdasJw.zip (36 KB)

CLAIM:

Beer's law was verified because our results showed that higher concentrations caused higher rates of red absorbance. This is proven by the line graph.

Scientific Explanation:

Throughout this lab I basically learned about what the concept of Beer's Law is. I also learned how to actually make a stock solution. It's important that each solution had the exact right amounts to help verify Beer's Law. The results I gathered proves that the more concentrated a solution is the more absorbant it is.

Question: Will a solution become less concentrated after dropping water in it multiple times? 

ABSTRACT:

    This experiment I did with my partner Victor deals with a blue solution and we wanted to see how concentrated it was. Our main goals for the experiment were to get familiar with using a Pasco SPARK System and to learn how to make a standard serial dilution. We also conducted this experiment to learn how to use a technique called colorimetry which is measuring a concentration of a solution. A problem we ran into was trying to fix the system to make it calibrate. We fixed it by putting distilled water in the glass cuvettes and we wiped it to make the readings more accurate. In the end test tube 6 had the highest % transmittance which was 101.1 The first two test tubes had a %transmittance of 0 because the concentration in them were still very high.

It seems like the bluing solution became less and less concentrated as we kept repeating our dilution process. The solution allowed a lot of light to shine through the test tubes after test tube 3.

SAFETY CONSIDERATIONS:

• Wash hands before and after the experiment
• Wear Safety Glasses
• Make space for materials
• Be careful when working with test tubes and systems.

MATERIALS:

• Lquid Bluing Solution
• Dilution Well Plate
• Plastic Dropper
• Distilled Water
• 10 Glass test tubes or 6(because the process takes a lot of time and sometimes the Pasco system has technical difficulties)
• Pasco Spark with Colorimeter
• Glass Cuvettes
• Test tube brush
• Safety Glasses

PROCEDURE:

1. Label the test tubes
2. Place 5ml of the liquid bluing solutions in test tube 1.
3. Take 0.5ml which is exactly 12 drops from test tube 1 and put it into test tube 2.
4. After that use a clean dropper and add 4.5ml of distilled water to the 0.5 ml of original solution that you had put into test tube 2.
5. Repeat the dilution process until you can barely see the blue dye in the test tubes.
6. Next you want to hook up the Pasco system and cords
7. Then conncet the cord and calibrate once you turn the system on.
8. To measure the solutions from the tubes, take them and pour them into a glass cuvette.
9. Measure the transmittance of each test tube.
10. Record all of your results and clean up the area.
    

EVIDENCE COLLECTED:

Test Tubes          Conc.         Transmittance

#1                         1x                    0

#2                        0.1x                  0

#3                        0.01x               0.1

#4                       0.001x             45.6

#5                       0.0001x           98.4

#6                      0.00001x         101.1

CLAIM:

The liquid bluing solution became less concentrated after distilled water was added into each test tube with .5 ml of the solution.

SCIENTIFIC EXPLANATION:

I learned while doing this experiment how to measure the concentrations of solutions. I also learned how to use the Pasco SPARK SYSTEM and also learned how to make a standard serial dilutio n. The test tubes all had different concentrations but they still allowed light to shine through. We just used a technique called colorimetry looking at how concentrated the soltuions were. The experiment definitely help us get familar with the PASCO SPARK SYSTEM.

Importance of Standard Model

The standard model has become an important and helpful tool to scientists because it shows the current particles and forces that scientists have discovered dating all the way back to the 1800's. The model helps scientists distinguish types of forces acting on particles. In the model you could find descriptions of particles and forces gathered up together so scientists could be able to keep track of particles they are discovering. Scietntists use the model to calculate and explain many many particle interactions that's why it's a very important tool for them.

Classification

Subatomic particles are classified by their charges and scientists sorted out most of the particles depending on their force and interactions too. Particles that have all kinds of known interactions (strong,electromagnetic,weak,gravitational,) are hadrons which are quarks and gluons. Particles that don't have strong interactions are mostly charged leptons. Others without an electirc charge have weak and gravitational interactions.

Modifications

The standard model will have more modifications in the near future. There are more particles that need to be discovered. Scientists may have to create a new model to have more space and room for future particles. The standard model is still not complete. It's just a unique model for now.

Finding Densities

Research Question:

In what level will each object float? How will the objects fall in the density column?

Abstract:

We conducted the experiment to get familiar with how to use lab equipments and to review how to calculate and find densities of substances with a partner.We also did the experiment to make predicitions and observations.The problem was finding the volume and mass so that we could calculate the density. We solved the problem by using a graduated cylinder,gram weight scale, and a ruler to find the voume and mass. In the end we found the densities of our substances.

Safety Considerations:

• Wash our hands

Materials:

• Ruler
• Graduated Cylinder
• Weight Gram Scale
• 7 substances

Procedures:

1. Get all 7 substances
2. Find mass of all substances first.
3. Find volume
4. Calculate Density

Evidence Collected:

Density of 7 Objects

Corn Syrup: 1.38g/ml

Water: 1.0 g/ml

Canola Oil: 0.92 g/ml

Parafin Wax: 9.49g/9ml=1.05 g/ml

Brass:34.42g/4ml=8.61g/ml

Steel:31.51g/4ml=7.88g/ml

Cork:1.15g/12ml=.10g/ml

Zinc:4.44g/1ml=4.44g/ml

Acrylic: 4.82g/4ml=4.44g/ml

Low Density Polyeth.: .04g/.3ml=.13 g/ml

Claim:

Scientific Explaination:

Resources: