Research Question: What is the enthalpy of the reaction between magnesium and hydrochloric acid?

Abstract: The experiment was performed to determine the enthalpy of the reaction between Mg and HCl experimentally and confirm with the theoretical calculations.

Safety Considerations:

Materials:

Procedures:

1. Put on safety glasses.
2. Collect all materials 
3. Measure 50.0mL of 1.0M HCl and pour into calorimeter.
4. Record the mass of the calorimeter and HCl and starting temperature of HCl
5. Measure out 0.2g of magnesium ribbon. Roll into a loose ball. Place the Mg into the HCl and quickly place the lids on the calorimeter
6. Record the temperature every 15 seconds.
7. When the reaction is complete, record the final temperature.
8. Clean up the lab area.

1. Write the correct balanced equation
2. Calculate the heat absorbed by the HCl
3. Convert this enthalpy into kJ
4. Calculate the number of moles of Mg.
5. Divide the heat given off (Q) by the number of moles of Mg used.
6. Calculate the "theoretical" heat of reaction (MgCl2(aq)= -801.15 kJ/mol)
7. Determine your percent error.

Evidence Collected:

   Time               Temp

Massof Calorimeter + HCl > 78.93 g

1. Mg + 2HCl --> H2 + MgCl2

2. Q= 36.5 x 4.2 x 17.8 = 2728.7 J

3. 2.78 kJ

4. 5.487 x 10E-3 mol HCl

5. -497.1751412kJ

6. -466.75kJ

7. 6%

Claim: Our experimental heat of reaction was a release of 497.1751412kJ. Our percent error was low at a 6%

Scientific Explanation: 'Some reactions give off energy, some absorb energy.' In this experiment, we learned the concept of enthalpy and in this experiment it gave off energy.

Research Question: How are concentration and pH correlated in strong vs. weak acids and bases.

Abstract: This experiment was conducted to see the correlation between pH and concentration. The problem adressed was what determined strong vs weak in acids and bases. The methods were the use of the Spark system and pH probe. The major results obtained was that correlation did exist between concentration and pH. Overall, the high and low concentration correlated with where it is located on the pH scale.

Safety Considerations: Safety Glasses worn at all times and gloves where optional.

Materials:

• Spark system with pH probe
• Beakers
• Distilled water
• HCL
• KOH
• Acetate
• NH4OH
• pH paper
• Graduated Cylinder

Procedure:

1. Create a table
2. Dilute all the chemicals
3. Test pH of all the solutions with the pH probe and record.
4. Complete the table using what you just found.

Evidence Collected:

Click here to download:

pH.docx (20 KB)

(download)

Click here to download:

pH.docx (20 KB)

Claim: Correlation between pH and concentration is that the higher the concentration of [H+], the lower the pH and the lower the concentration of [H+], the higher the pH.

Scientific Explanation: As concentration of the solution increased for the acids so did its hydrogen ion concentration. The data showed how HCl has a high concentration of [H+], therefore, it had a low pH of 2.35. Higher [H+] made for a stronger acid and, vice versa, the lower [H+] made for a weaker acid. This differed for the bases. As the concentraion of the basic solution increased, its hydrogen ion concentration decreased. The date showed how KOH had a low concentration of [H+] of about 8.1E-14, therefore, KOH had a high pH of 13.09. So, lower [H+] of a base meant stronger base and higher [H+] made for a weaker base. After all, pH is the measure of the concentration of hydrogen ions in a solution.

or

Higher Conc. of Solution ---> Higher [H+] ---> Lower pH ---> Stronger acid

Lower Conc. of Solution ---> Lower [H+] ---> Higher pH ---> Weaker acid

Higher Conc. of Solution ---> Lower [H+] ---> Higher pH ---> Stronger base

Lower Conc. of Solution ---> Higher [H+] ---> Lower pH ---> Weaker base

Research Question:

Can we verify Beer's Law using colorimetry?

Abstract:

This experiment was conducted to understand and verify Beer's Law. The porblem being addressed was the verification of Beer's Law. The method we used to solve the problem was a technique called Colorimetry. The major result obtained was that as the red absorbance increases, the concetration of CuSO4 increases too. As a whole, we verified Beer's Law that absorbance and concentration are proportional to each other.

Safety Considerations:

We wore safety goggles at all times when doing the lab. Before and after each lab, we washed our hands.

Materials:

• Test Tubes and Holder
• Distilled Water
• Graduated Cylinder
• 25mL Volumetric Flask
• Pipets
• Copper(II) Sulfate
• Scale
• Pasco SPARK System w/ Colorimeter
• Glass Cuvettes

Procedure:

1. Create and fill the Concentration chart. 
2. Create a stock solution by measuring 3.121g of Copper (II) Sulfate using the scale. Pour the Copper (II) Sulfate into the flask and fill to the 25mL line with distilled water. Cover the flask with a cork and shake until the CuSO4 dissolves.
3. Label test tubes.
4. Create dilutions from the chart into different test tubes.
5. Set up the Pasco SPARK System and calibrate the Colorimetry.
6. Measure the RED ABSORBANCE of your solutions by putting them into the glass cuvettes.
7. Place in colorimetry and record the RED ABSORBANCE from the Pasco SPARK System in your chart. Repeat for every solution.
8. After your done measuring RED ABSORBANCE and recording, clean lab and wash all the glass equipment.
9. Create a standard curve using Excell from your chart of the Concentration of Final Solution and Red Absorbance (Y Axis: Red Absorbance; X Axis: CuSO40).

Evidence Collected:

Chart:

Standard Curve:

Claim:

We were able to verify Beer's Law because our standard curve showed how absorbance is proportional to concentration.

Scientific Explanation:

I learned the concept of Beer's Law through performing a lab. I was able to verify Beer's Law because our results demonstrated that as the absorbance increased so did the concentration and vice versa. Beer's Law claims that AαB, so, in our case, absorbance is proportional to concentration and vise versa.

Research: Measuring the concetration of a solution using a technique called 'colorimetry.'

Abstract:

• The experiment was conducted to familiarize with the Pasco SPARK system and to deal with making standard serial dilution.
• The problem being addressed was how to dilute the bluing solution.
• Methods being used where different trials of extraction from the previous concentrations.
• It took six trials to dilute the bluing to 100%+.
• Concentration decreases transmittance.

Safety Considerations:

• Safety glasses worn before entering lab.
• Wash hands before and after lab.
• Carefull with glass($7 a piece)

Material:

• Liqued Bluing Solution
• Dilution well plate
• Plastic Dropper
• Distilled water
• 10-glass test tubes
• Pasco SPARK w/ colorimeter
• Glass cuvettes

Data:

Claim:

The more you add water the less concentrated it becomes.

Scientific Explanation:

The colorimetry showed that the more transmittance, the less concetration.

--Why has the Standard Model become such an important tool for scientists?

Physicists use the Standard Model to theorize and to experiment different particles.  The scientists have used the standard model to help search for new physics beyond the Standard Model from relatively uninteresting background. The Standard Model groups major theories into a consistent theory that describes the interactions between all known particles which scientist use to find other unknown particles.

--Explain how subatomic particles are classified. Include information about the properties used to classify.

Subatomic particles are either fermoins or bosons. They are determined by their spin. Fermoins have a spin of 1/2 while bosons have a spin of 1. Fermoins can futher be classified as either a quark or a lepton.

--Describe any updates of modifications you could see coming to the Standard Model during your lifetime.

I can see more unknown particles to be added to the standard model and perhaps Higgs boson to be confirmed rather than just being hypothethical.

Density Lab

Research Question: In what level will each object float?

Abstract: We conducted the experiment so that we can get familiar with the lab equipment and also have some review on density. The problem we were trying to solve was where each object would float. To solve this, we had to use a ruler, gruaduted cylinder, and a scale that measured in grams. In order to find the density of each object we used the technique of water displacement to find volume. And the scale to find mass. My major results were that not all objects would float on the same level.

Safety Consideration: Washed hands at the end of each lab session.

Materials:

• Ruler
• Gruaduted Cylinder
• Scale (grams)
• Glass Stick
• 7 Substances

Procedure:

1. Find Mass (weigh each item on the scale)
2. Find Volume (use water displacement technique)
3. Find Density (divide mass over volume)
4. Research Density for Corn Syrup, Canola Oil and Water

Evidence Collected:

Mass--Volume--Density

Parafin Wax: 9.49g--9mL--1.05g/mL

Brass: 34.42g--4mL--8.61g/mL

Steel: 31.51g--12ml--7.88g/mL

Cork: 1.15g--12mL--.10g/mL

Zinc: 4.44g--1mL--4.44g/mL

Acrylic: 4.82g--4mL--1.21g/mL

Low density Polyethyloye: .04g--.3mL--.13g/mL

Claim: The cork, parafin wax, and LDP fell in the canola oil level. The acrylic fell just a little below water. And the zinc, steel, and brass fell right to the bottom level, the corn syrup.

Scientific Explanation: Density determines where each object would fall into what level. The reason of this is due that the three liquids have different densities from each others.

Resources: Internet