Redox Lab

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 react with a known amount of copper II sulfate pentahydrate and to compare this to the actual yield of copper.

Background Information:
Copper precipitate is a by product of the reaction between aluminum and copper sulfate.
Oxidation is the loss of electrons or an increase in oxidation state by a molecule,ion, or atom. Reduction is the gain of electrons or a decrease in oxidation state by a molecule, ion, or atom.
Actual yield: It is given as the weight in grams or in moles.Theoretical Yield:The quantity of a product obtained from the complete conversion of the limiting reactant in a chemical reaction. Theoretical yield is commonly expressed in the terms of grams or moles. Percentage yield: Calculate to be the experimental yield divided by theoretical yield multiplied by a hundred percent.


















Materials:

1. Aluminum
2. Copper sulfate pentahydrate
3. Beaker
4. Stirring rod
5. Filter

Safety Per cations:

1. Safety goggles
2. Apron
3. Clamps

Procedure:

1. Obtain a medium sized beaker
2. Add 75-100 mL of water to beaker; set-up apparatus to heat your mixture over a Bunsen burner to begin heating.
3. Measure out about 15 g of Copper(II) Sulfate Pentahydrate (CuSO4 . 5H2O) and record the mass in the data 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 a piece of aluminum foil that weighs between 0.7 and 1.0 grams. Record the mass exactly into the data table (hundredths place).
6. Tear the foil into small pieces and carefully add it to the hot solution with continuous stirring until all the foil is placed into the beaker.
7. Stirring frequently, allow the reaction to occur until you can't see any more sliver 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 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 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 the residue and record the mass in the data table, Throw the paper and residue away.

Analysis:






1. 3Cu(SO4) + 2Al --> 3Cu + Al2(SO4)3

2. .62g Al x 1molAl/26.98g x 3 mol Cu/ 2 mol Al x 63.546 g Cu/ 1 mol Cu= 2.19g Cu (theoretical yield)

3. The actual yield measured was 1.53g Cu.

4. 1.53/2.19= .6986= 69.86% Yield

5. Reasons why we only got ~ 70% of the Copper that had been predicted.

We might not of spent enough time during the expirement to allow all of the Aluminum to react with the Copper Sulfate-Pentahydrate.

Our expirement techniques heating, precipitate gathering, etc. might of caused some the the copper to not get caught by the filter.

Byproducts may have been created that could have subtracted some of the Cu from our precipitate that could have not been measured and disposed of with the waste.

Conclusion: In the duration of the lab we determined the number of grams of Cu that was produced from oxidation reduction reaction and compared the mass of Al that reacted with the Cu II Sulfate pentahydrate to the actual yield of Cu. This lab was extremely helpful in the learning process on how balance equations, how figuring out the reaction before hand in your balanced equation is a great idea to discuss and make a hypothesis. Thank you for reading our blog, hopefully you will get out there and try it on your own and then follow up with a blog of your own and a comparison!

Reactions Lab

Intro:
the five types of reactions:
•Combustion reaction - 2 Oxygen molecules and extra energy are released. It is violent exothermic reaction with oxygen to form oxide(s).
•Synthesis reactions - (also know as direct combination reactions) atoms or simple molecules combine to form a more complex compound.
•Decomposition reactions - one compound breaks down to produce two or more simpler substances.
•Single displacement reactions - one element replaces another in a compound that is in a solution.
•Double displacement reactions - ions from two compounds interact in a solution to form a product.

this is an example of double displacement in the way of the two couples interchanging partners as if they were positive and negative, attracting the partner of the opposite couple. This is the metals changing polyatomic anions.










Procedure:
Obtain 3 test tubes
In one, place a piece of zinc and about 1/2 mL of CuSO4.
In another, add about 1/2 mL of Ba(NO3)2 solution to about 1/2 mL of CuSO4 solution.
In the third, place a piece of magnesium ribbon. add about 1/2 mL of HCl solution.
record all observations
Light a bunsen burner, recording observations of flame
rinse out first test tube and add about 2 mL of H2O2 solution. LIGHTLY heat it and record observations.
Add a pinch of MnO2 to the H2O2 solution. LIGHTLY heat it and record observations.


Results:

reactant	observations	products	Reaction type
zinc and CuSO4	In the first test tube with zinc and CuSO4, copper precipitate formed on the zinc. The reaction was single displacement.	Cu and ZnSO4	single displacement
Ba(NO3)2 and CuSO4	In the second test tube containing Ba(NO3)2 and CuSO4, there were bubbles meaning gases were released and white powder formed at the bottom of the tube. The was an example of a double displacement reactions.	BaSO4 and Cu(NO3)2	double displacement
Mg and HCl	In the third test tube with the magnesium ribbon and HCl, lots of bubbles formed and the solution gave off heat. This was a single displacement reaction.	H2 and MgCl2	single displacement
C3H8 and O2	Bunson burner - the flame is dark blue at the opening where the C3H8 was release. Surrounding that was a lighter blue and at the very tip was orange.	CO2 and H2O	combustion
H2O2	Higher boiling point? The solution bubbled black. Flame place over the gas was extinguished.	H2O and O2

Chemical Reactions:










Zn + CuSo4 -> Cu + ZnSo4












Ba(No3)2 + CuSo4 -> BaSo4 + Cu(No3)2














Mg + HCl -> H2 + MgCl2














C3H8 + O2 -> Co2 + H2O














H2O8 -> H2O + O2


Conclusion
As a result of mixing the substances we found many different reaction types depending on what items we mixed together. In this lab we recorded all observations while working and continued to identify the type of reaction followed by writing the correct balanced equation.

Molecule Shape Lab

Background Information: Covalent bonding is the most common type of bond. When two or more atoms share a pair of electrons a covalent bond is formed. A polar covalent bond is formed when atoms have different electronegativities. The electrons are attracted to the atom with the higher electronegativity. On the other hand, if both atoms have the same electronegativity the bond is then nonpolar covalent. In the experiment we will be conducting, we will be constructing models of molecules and deciphering their polarity based on their shape.

Materials: 1 Model Kit including 5 carbon atoms, 15 regular bonding shafts, 5 bendy bonding shafts, 7 oxygen atoms, 3 nitrogen atoms, 8 hydrogen atoms, 6 fluorine atoms, also we had reference work sheets of the geometry of molecules.

Procedure: Draw the lewis structure for the sixteen elements then make 3D models of each. after constructing the 3D models we were to draw 2D pictures on the worksheet. after all the diagrams were made and drawn out we had to write out the molecular geometry, bond angle, polarity and whether or not it was a resonance structure.

H2O



Linear
90 degree bond angle
polar
















C3H8




Tetrahedron
109.5 degree bond angle
polar















CH4



tetrahedron
109.5 degree bond angle
nonpolar


















BF3




trigonalplaner
120 degree bond angle
nonpolar














SF6



Octet
90 degree bond angle
polar


















Conclusion: We found that only one of the molecules was a resonance structure and that all the molecules followed the octet rule.
The models and the lewis structures don't necessarily look alike.

Chromatography Lab Report

Safety precautions:

•closed toe shoes

•protective aprons and eye wear
•keep solvents under fume hood (hexane)


Task at hand:
Determine the reaction of certain solvents (H2O, C6H14, CH3OH, C3H7OH) with different colored inks while staying safe and using the proper materials.

♦PART I

Hypothesis:
Water would be the best solvent because in previous experiences while using black ink, water was spilled and the ink turned colorful and spread throughout the page.

Materials:
-overhead black ink pen
-4 cut strips of filter paper (approx. 1cm x 8cm)
-well plate
-(opt.) graduated cylinder
-4 solutions
-hexane (C6H14)
-methanol (CH3OH)
-isopropyl (C3H7OH)
-water (H2O)

○Procedure:
1) fill four separate wells on the 24 well plate approximately half full of each of the four solvents.
2) make a right angle bend at one end of each filter paper strip approx. 1.5 cm from end.
3) mark a pencil line near the crease of each fold
4) Make multiple ink blots on each crease of filter paper
5) Place the small end of each filter paper into filled wells.
-place long end up strips on graduated cylinder to help progress
6) Allow solvents to wick up the papers for about 30 minutes.
7) Record observations.




○Observations:
The strip dipped in water progressed the most and is the most colorful. The second most colorful was the strip dipped in methanol. The colors fan out toward edges the farther the travel up the strips. The hexane is making the black dot thicker but doesn't actually separate colors. Isopropyl slowly spread the black up the paper but the colors consist of only black and dark blue. On January 28, 2010, the stop time for the solvents and reactions was 11:04 am.

○Results:

♦PART II

Hypothesis:
With water, green will be the one made of the most colors because it's the only one being used that isn't a base color.

materials:
-4 different colored markers
-green, orange, blue, red
-4 wells filled with H2O
-4 cut strips of filter paper (approx. 1cm x 8cm)
-(opt.) graduated cylinder

○Procedure:
1.) Repeat steps 1-7 in PART I with 4 different colored inks

○Results:

Green, with the widest variety of color, was the only mixture in the group of colors. Of the pure (base) colors, red ranged the most in color from light pink to dark red, and blue and orange had very little variety at all.

♦CONCLUSION:
Water was proven the best solvent for the chromatography lab as its polarity separated the colors the most efficiently
While doing the experiment, we learned how different solvents react to the pigments in the ink

1) In PART I, the solvents ranked from best to worst for the separation as: H2O, CH3OH, C3H7OH, and C6H14

2) Some solvents worked better than other did on the ink because some had stronger polarities and attracted other atoms more efficiently

3) The ink in the black pen is a mixture, as shown by the multiple colors on the strip

4) C6H14 wasn't an appropriate solvent from PART I to use for PART II. Because of its weak polarity, it was the least capable of the solvents for the experiment

5) Blue, orange and red were classified as pure substances, whereas the green was a mixture

6) Chomatography is a technique for separating components of a mixture by placing the mixture in a mobile phase that is passed over a stationary phase.