Redox Lab

Aluminum & Copper II Sulfate Redox Lab

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Purpose:]

To determine the number of grams of copper that will be produced from an oxidation reduction reaction when you know the mass of Aluminum that reacted with a known amount of copper II sulfate pentahydrate and to compare this to the actual yield of copper.

Materials & Setup…

You will obtain a measured sample of aluminum foil and a measured amount of copper sulfate pentahydrate. You will then react the two in an aqueous medium within a medium sized beaker; stirring frequently. You will filter, dry, and weigh the resulting product.

Materials needed:

75-100ml beaker
75-100ml water
8-10g copper (II) sulfate pentahydrate (CuSO45H2O)CuSO4 • 5H2O

Procedure:

1. Obtain a medium sized (250 to 400ml) beaker.
2. Add 75 to 100ml of water to beaker; set-up apparatus to heat your mixture over a Bunsen burner to begin heating.
3. Measure out 8 to 10g of Copper (II) Sulfate pentahydrate (CuSO4 • 5 H2O) and record the mass in the table. Then slowly add the crystals to the heating water.
4. With a glass stirring-rod, stir the solution until the Copper II sulfate pentahydrate is dissolved.
5. While the copper sulfate crystals are dissolving one member of the group can go and get the foil. Carefully weigh out aluminum that weighs between 0.4 and 0.7 grams. Record the mass exactly into the data table (thousandths place).
6. Carefully add aluminum to the hot solution with continuous stirring until the foil is placed into the beaker.
7. Stirring frequently allow the reaction occur until you can’t see any more silvery foil pieces. This will take 15 to 20 minutes so be patient. Once you can’t see anymore foil pieces no matter how small, heat it an additional 3 to 4 minutes, then remove from heat.
8. Write your names around the outside edge of a filter paper (so you can claim it later), weigh and record the mass in the data table.
9. Use the filter paper and your funnel to filter the residue in the beaker, catching the filtrate into the Erlenmeyer flask provided.
10. Rinse out your beaker with a small (amount just covering the bottom of the beaker) of water to be sure you obtained all of the product/residue.
11. Remove the filter paper from the funnel and spread it out on a paper towel to dry overnight.
12. Clean and dry the glassware. Be sure the propane is turned off and Bunsen burner disconnected and put away. Straighten up your area.
13. Upon returning the next day. Weigh the filter paper and dry residue and record theat mass in the data table. Throw the filter paper and residue away.

Just for a HARDER thought…..

1. Write the balanced reaction equation.

2. Write the net ionic equation.

3. What is the reducing agent and what is the oxidizing agent?

4. Use the mass of Al dust and calculate the mass of the copper you theoretically would form.

5. Subtract the filter paper from the dry residue/product in the data table. This is your actual yield of copper.

6. Calculate the percent yield of this experiment.

7.Give three reasons of why the amount of copper that should have formed and the amount of copper that actually formed might be different.

REACTION LAB

Introduction:

In this lab we performed various chemical reactions in a lab. We recorded our observations then identified the type of reaction and wrote a balanced chemical equation.

Purpose:

The purpose of this lab is to become more familiar with the five types of chemical reactions below.

Types of Reactions:

Combustion: A violent exothermic reaction usually with oxygen or oxides.

16KCl₃ + 3P₄S₃ --> 16 KCl + 9SO₂

Decomposition: A reaction in which a single compound is broken down to produce two or more simpler substances.





Single Displacement: Chemical reaction in which one element replaces another element in a compound that is in solution.







Double Displacement: Chemical reaction in which ions from two compounds interact in solution to form a product.




Synthesis: Chemical reaction in which atoms or simple molecules combine to form a compound that is more complex.










Procedure:

1. Obtain 3 small test tubes.
2. In the first test tube, place a piece of zinc and about 1/2 mL of CuSO4 solution. Record observations.
3. In the second test tube add about 1/2 mL Ba(NO3)2 solution to about 1/2 mL of CuSO4 solution. Record observations.
4. In the third test tube place a piece of magnesium ribbon. Add about 1/2 mL of HCl solution. Record observations.
5. Light a bunsen burner (burning propane gas, C3H8). Record observations of the flame.
6. Rinse out the first test tube. Add about 2 mL H2O2 solution. Lightly heat it. Record observations
7. Add a pinch of MnO2 (catalyst) to the H2O2 solution. Lightly heat it. Record observations

Data/Results:

1. Zn + CuSO₄ Cu + ZnSO₄

Single Displacement

2. Ba(NO₃)₂ + CuSO₄ à BaSO₄ + Cu(NO₃)₂

Double Displacement

3. Mg + 2HCl à H₂ + MgCl₂

Single Displacement

4. C₃H₈ + 5O₂ à 3CO₂ + 4H₂O

Combustion

5. 2H₂O₂ à 2H₂O + O₂

Decomposition


Conclusion:

In this lab we performed the several different types of reactions. After performing these reactions we wrote down the chemical equations for each reaction and determined whether it was synthesis, double displacement, single displacement, combustion, and decomposition. By creating these we reactions we can now better understand what to look for for each reaction.

Polarity and Molecular Shapes

OBJECTIVES:
-Construct models like molecules
-Determine molecular shape
-Predict polarity of molecules
MATERIALS:
-Molecular Model Kit
PROCEDURE:
1) Build a model for your selected molecules.
2) Draw a three-dimensional structure of each molecule . Use solid lines to represent bonds in the plane of the paper, dashed lines for bonds that point back from the plane of the paper, and wedged lines for bonds that point out from the plane of the paper toward the viewer.
3) In a table, note the shape of each molecule, the bond angles, whether or not they will be polar, and whether or not they exhibit resonance structure.
ANALYSIS:
1) Explain how water shape causes it to be polar.
2) Describe how water’s properties would be different if the molecules were linear instead of bent.
3) Based on the results of this experiment, list the molecules from the experiment that would be water-soluble.
Here are some examples:
C2H4
compares to

C3H8

Chromatography Lab

Statement of The Problem-

Out of four solutions, which solvent will have the most effect on drawing out the pigments in each color?

The purpose of the Paper Chromatography Lab is to compare different solvents’ polarity and ability to separate a mixture into its pure components.

Solvents:

H₂0

CH₃OH

C₃H₇OH

C₆H₁₄

Materials-

(Part 1) Black over-head pen (Part 2) Red, Yellow, Green, Purple, and Purple pens.

Solid Phase: 10 Chromatography paper strips

PART 1 Procedure-Test to see which solvent works the best in the separation of the mixture found in black ink.

1) Pick one color over-head pen (black) to test with different solvents.

2) Cut four strips of filter paper approximately 1 cm x 8 cm

3)Make a right angle bend at the end of the paper approximately 1.5cm from one end.

4)Put a pencil line near the crease and dot the ink to be tested several times on the pencil line.
(allow a few seconds between dots for ink to dry)

• Using pencil, label each strip as to which solvent will be used.

5) Fill 4 separate wells on the 24 well-plate approximately 1/2 full of the solvents.

6) Place your paper strips into the wells so that the short end is in the solvent.

7) Allow the solvent to wick up the paper for approximately 30 minutes. Record your observations.

Results-Conclusion

Out of the four solvents, H₂O left the longest trail of ink, in the fastest amount of time. CH₃OH followed slightly slower and did not bleed out as far as water. C₆H₁₄ came third, this solvent is not as polar as the first two, so it made sense that it did not reach the same distance. C₃H₇OH is not polar what-so-ever, therefore, did not bleed out at all. In this case, H₂O was the best solvent you can use for this lab since the only other solvent that worked somewhat decent was CH₃OH.

PART 2 Procedure- Choose a single solvent from Part 1 and test its ability to separate different colors.

1) Repeat steps (1-4) outlined in the above procedure with different colored inks. (4-5 strips depending on how many colors you use)

· Be sure to label the strips into the wells so that the short end is in the solvent.

4) Fill 4-5 wells half full of the solvent

5) Place your paper strips into the wells so that the short end is in the solvent.

6) ALLOW THE SOLVENT TO WICK UP THE PAPER FOR APPROX. ½ HOUR.