Thursday, May 20, 2010

Al & Cu II Sulfate Redox Lab

The purpose of this lab was to determine the number of grams of copper that will be produced for an oxidation reduction reaction when you know the mass of Aluminum that reacts with a known amount of copper II sulfate pentahydrate and to compare this to the actual yield of Copper.

Materials:
Aluminum
Copper sulfate pentahydrate
Water
Beaker
Scale
Glass stirring rod
Bunsen burner
Filter paper

Procedure:
1.Obtain a 250 to 400ml sized beaker.
2.Add 150 to 200ml of water to 250 to 400ml beaker; set-up apparatus to heat your mixture over a Bunsen burner to begin heating.

3.Measure out 10 g of Copper 2 Sulfate pentahydrate ( CuSO4. 5 H2O) 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 2 sulfate pentahydrate is dissolved.

5.While the copper Sulfate Crystals are dissolving one member of the group can go and get the Aluminum Powder. Carefully weigh out the powder to weight between 0.4-0.7 grams. Record the mass exactly into the data table (thousandths place).

6.Carefully add the powder to the hot solution with continuous stirring until it is all in the beaker.

7.Stirring frequently allow the reaction to occur until you can't see anymore aluminum. This will take 15 to 20 minutes so be patient. Once you can't see anymore Aluminum, heat an additional 3 to 4 minutes, then remove from the heat.

8.Write your names around the edge of a filter paper (so you can claim it later), weight 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 of 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 the mass in the data table. Throw the filter paper and residue away.
14.Construct a Data Table with the following parts:

1. Mass of Copper(II) Sulfate Pentahydrate
2. Mass of Aluminum foil
3. Mass of Coffee Filter
4. Mass of dry residue/product + Filter Paper

Thursday, March 18, 2010

Types of Reactions Lab

Introduction and Background

Synthesis- the formation of a compound.
Decomposition- 1 reactant. 2 or more products. cations and anions switch with each other.
Single Displacement- one element takes the place of another.
Double Displacement- metal takes the place of a metal.
Combustion- Hydro Carbon.

Zn+CuSO4 -> Cu+ZnSO4



Ba(NO3)2+CuSO4 -> BaSO4+Cu(NO3)2




Mg+HCl -> H2+MgCl2



C3H8+O2 -> CO2+ H2O



H2O2 -> H2O+O2

Friday, February 19, 2010

Modeling Lab

The purpose of this lab was to be able to better understand and recognize molecular structures and polarity.


HF



H2O2



CH3NH2



C3H8
























CH4


PROCEDURES:



1) build a model for each of the molecules listed on the data table on the back of this page.





2) Draw the tree-dimensional structure of each molecule table 1. Use solid lines to represent bonds in the plane of the paper, dashed lines for bonds that point back form the plane of the paper, and wedged lines for bonds that point out from the plane of the paper toward viewer.


3) Note the shape of each molecule in the third column of table 1, the bond angles in column 4, whether or not they will be polar in column 5, and whether or not they exhibit resonance structure in column 6.











From our experiment, we have observed and learned that there is much more to molecular shape than meets the eye. Some have double bonds or even triple bonds or many more pairs of electrons than you would have thought.

Thursday, February 4, 2010

Chromatography and Pigments

The mobile phase of the experiments are the solvents which include H2O, CH3OH, C3H7OH, and C6H14. The stationary phase is the paper strips we used during the lab. Retention time was how long the solvent held onto the pigment. The farther the pigments went, the longer retention time. A polar molecule will be better at carrying the pigments because it is stickier than a non polar molecule. Our prediction was that C3H7OH would be the best solvent.



In part 1, our first step was to fill four of the wells in the well tray half full of different solvents. We then took chromatography paper and put 3 or 4 dots using black ink. The paper had a right angle bend 1.5 cm from the end. Then we placed the strips in the solvents. After about a half an hour, we observed what had happened to the pigments of the ink





Our observations from part one were that water was the most affective solvent at carrying pigments. Followed by methanol, escpropy, and hexane.

The next day we repeated the experiment using H2O because it was the best solution at spreading the pigments.

Safety Procedures: Apron, goggles, hair tied back, keeping solvents under the fume hood to avoid headaches, closed shoes and no bulky clothing.