brownbhhs's posterous

Heat of Reaction Lab Write-up

I. TITLE and/or RESEARCH QUESTION: How can we find the enthalpy using a lab? 
 
II. ABSTRACT: The heat of reaction lab was conducted to see how to find the enthalpy during a reaction in a lab. Using the reaction of magnesium and hydrochloric acid we collected data and used reaction equations to find the enthalpy. As the experiment went on the temperature rose as the two items reacted with another. We knew the reaction was complete when the temperature stopped moving. Overall, the conclusion of the experiment is that finding the enthalpy of a reaction in a lab is possible using the right data.
 
III. SAFETY CONSIDERATIONS

  • The reaction can give off irritating vapors - keep calorimeter lids ON at all times, and work at arm's distance.
  • 1M HCl will irritate skin; wash off immediately if contacted

     IV. MATERIALS: 

  • styrofoam calorimeter
  • 1.0M HCl
  • magnesium ribbon
  • thermometer

     V. PROCEDURE:

    1. Collect all equipment and put on your 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 loose 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 the waste container, with an equal volume of tap water to "neutralize" any remaining acid.
    10. Clean off your lab table and return to your seat.

    • VI. EVIDENCE COLLECTED: Calorimeter- 33.18g w/HCL 82.75g

    Start Temp- 24.4(C)

    End Temp-37.4(C)


    VII. CLAIM: By using a reaction,relevant data, and reaction equations we can find the enthalpy of a reaction in a lab.
     
    VIII. SCIENTIFIC EXPLANATION THE MOST IMPORTANT PART OF
    THE LAB!!! By doing this lab i learned how to calculate the enthalpy of a reaction in a different way other than just plugging in numbers into an equation. i also learned that a reaction has many componets involved in the process.

    Biorenewables paper feedback

    The feedback that i recieved was simple yet helpful. He seems like he wants to guide me in the right direction. The comments he provided made a lot of sense and will definitely help me write a better paper.

    • change of cover
    • new introduction
    • better wording in the body

     

     

    pH Lab Write-Up

    RESEARCH QUESTION

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

    ABSTRACT

    The pH experiment was conducted to determine if the higher the concentration, the higher the level of pH either weak or strong. A problem that had to be delt with during the tests was reading the pH paper and converting the data that was collected. Some methods that were used during the lab were diluting the acid or base and then testing the pH level. The major results obtained were that the less concentrated the solution was , the more neutral the pH level was. The overall conclusion to the lab is that there is a strong correlation between pH and concentration.

    SAFETY CONSIDERATIONS

  • Safety glasses should be worn at all times.
  • Acids and bases are hazardous and should be handled accordingly.
  • Follow all written and verbal instructions.

    • MATERIALS

    • pH paper
    • acids/bases
    • Microfuge tubes

    PROCEDURE

    1. Obtain 0.1M solutions of a strong acid (HCl), strong base (KOH), weak acid (acetic acid), and weak base (NH4OH).
    2. Working in microfuge tubes, perform a serial dilution with each solution so you end up with 0.1M, 0.01M, 0.001M and 0.0001M solutions for EACH solution provided (4 solutions x 4 dilutions = 16 tubes total).
    3. Make sure your tubes are labeled as you go.
    4. Determine the pH of each solution by adding ONE DROP to a strip of pH paper. (alternatively, you may use the SPARK pH probe to determine pH)
    5. Then, calculate the [H+] for each solution
    6. Calculate the pOH and [OH-] of each solution
    7. Identify the solution as ‘strong’ or ‘weak’.

    EVIDENCE COLLECTED

    pH Lab Data
    Solution Concentration pH  [H+] pOH [OH] Strong/Weak
    HCL 0.1   3 0.001 11 1E-11  S 
    0.01   4 0.0001 10 1E-10  S
    0.001   7 0.0000001 7 0.0000001  S
    0.0001   6 0.000001 8 0.00000001  S
    KOH 0.1   11 1E-11 3 0.001  S
    0.01   10 1E-10 4 0.0001  S
    0.001   10 1E-10 4 0.0001  S
    0.0001   6 0.000001 8 0.00000001  S
    Acetic Acid 0.1   4 0.0001 10 1E-10  W
    0.01   5 0.00001 9 0.000000001  W
    0.001   4 0.0001 10 1E-10  W
    0.0001   6 0.000001 8 0.00000001  W
    NH4OH 0.1   10 1E-10 4 0.0001  W
    0.01   8 0.00000001 6 0.000001  W
    0.001   8 0.00000001 6 0.000001  W
    0.0001   6 0.000001 8 0.00000001  W

     CLAIM

    There is a strong correlation between concentration and pH level.

    SCIENTIFIC EXPLANATION

    During the pH lab, I as a student learned many different things when it comes to pH levels and how to test them. The most common technique, which was used in this lab, is pH paper. Another wy to test pH levels is the electronic device called SPARK. As my data shows , you can see that the correlation between the concentraion and pH levels is strong. For example with KOH you see that the more concentrated the solution the higher the pH level.

    Serial Dilution

    RESEARCH QUESTION

    Using Colorimetry, what concentration level let through the most light?

    ABSTRACT

     We conducted this experiment so we could test the levels of concentration and at which density let the most light pass through, the problem that we faced was that the colorimeter was a difficult device to use at first, and also learning how to dilute the solution using the tools given. The main method we used to find our results was to use the colorimeter and the glass cuvettes to shine light through and record the data, from this data we learned that it only took for steps of dilution to show a major resemblence to just distilled water. Overall we as a group came to the conclusion that even when there seems to be no solution in the cuvettes, 100% of the light didn't go through.

    SAFETY CONSIDERATIONS

    Safety glasses were worn at all time and if solution was exposed to skin, it was washed off ASAP

    MATERIALS

    • Blue Solution
    • Dilution well plate
    • plastic dropper
    • Distilled water
    • 10 glass test tubes
    • Pasco SPARK w/ colorimeter
    • Glass cuvettes

    PROCEDURE

    1. Label test tubes
    2. Place 5ml of liquid in test tube #1
    3. take 12 drops of liquid from test tube #1 and drop it into test tube #2, then add 4.5mL distilled water to original solution
    4. Repeat this procedure until all tubes are filled.

    EVIDENCE COLLECTED

    Test tube 1 = 0%

    Test tube 2 = 0%

    Test tube 3 = .8%

    Test tube 4 = 49.4%

    CLAIM

    The less solution we used , the more the light was passed through.

    SCIENTIFIC EXPLINATION

    From conducting these experiments, I learned that the least amount of light let through means that the concentration is at it's highest level.

     

     

     

     

     

     

    Subatomic

    The reason the standard model has became so important is because it gives a structure to the events occuring in protons neutrons and electrons. Now that we know what is happening we can label and place the actions on the standard model. Subatomic particles are classified by the mass, charge, and how long they survive. I see in the future that scientist break it down to a greater extent which will extend the table and create more classes.

    September 6, 2011

    Density Lab

     

    Research Question: Where would the objects land when dropped in the liquid?

    Abstract:

    The reason we did this experiment was to get used to finding density using volume and mass and also to make predictions using data.

    Safety Considerations:

    None

    Materials:

    • Water
    • Canola oil
    • Corn Syrup
    • Zinc
    • Acrylic
    • Brass
    • Steel
    • Cork
    • Graduated Cylinder

    Procedure:

    1. Weigh items
    2. Find volume of items
    3. Calculate Density
    4. Find Density of liquids
    5. Test each item

    Evidence Collected:

    • Wax - 23.41g
    • Cork - 1.36g
    • Steel - 31.49g
    • Brass - 34.21g
    • Acrylic - 4.71g
    • Zinc - 6.56g

    Claim:

    If the object was denser than the liquid it would go through that certain liquid.

    Scientific Explanation:

    The scientific expalination of this lab is quite simple and uses common sense. After weighing each item and finding the density of both the liquids and the items, we found that the denser the object the heavier it was, therefore it sunk to the bottom.