Types and Forms of Reactions

Introduction:
In this lab we performed various chemical reactions. We recorded our observations, identified the type of reactions, and wrote balanced chemical equations for each. The purpose of this lab is to become more familiar with the five types of chemical reactions.

Procedure:
1. Obtain 3 small test tubes
2. In the first test tube, place a piece of zinc about 1/2 mL of CuSO4n solution. Record observations.
3. In the second test tube add about 1/2 mL Ba(NO3) 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 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.

Chemical Reactions:
In our first test tube we put 1/2 mL of CuSO4 (copper Sulfate) which had a blue color to it and then added a piece of zinc which turned the liquid from blue to clear with actual copper metal forming at the bottom of the test tube.



In the second test tube we added about 1/2 mL of Ba(NO3)2 (Barium Nitrate) solution to about 1/2 mL of CuSO4 (Copper Sulfate) solution.The precipitate (which had a white solid texture to it) went to the bottom because of the density which was higher than the barium nitrate.



In the third test tube we placed a piece of magnesium ribbon, and about 1/2 mL of HCL solution. The solutions mixed fizzed and then the magnesium ribbon completely dissolved.The final solution was a clear liquid.



BE SURE TO CARRY OUT PROPER SAFETY PROCEDURES: GOGGLES, APRONS, AND BE SURE TO KEEP LIQUID CLOSE TO FUME HOOD!!



We then lit a bunsen burner (burning propane gas, C3H8). We used a striker to ignite our flame on the burner. The flame at first started out blue and then as it grew it turned to orange.

After we lit our burner we rinsed our first test tube and placed 2mL of H2O2 solution (hydrogen peroxide),after this we then heated it slowly. It caused the solution to start fizzing and bubbling, the longer we heated it the more it boiled. We were sure not to heat it to fast, if we did it would boil over.



After we recorded our observation we added a pinch of MnO2(catalyst) to the H2O2 solution. We then re-heated it. This caused the same boiling reaction and the color to change to thick gray. The gas was escaping so quickly that it caused a ring of gas and liquid to shoot up and out of the test tube.



We recorded our observations, By identifying the type of reactions and balancing chemical equations for each. We were able to become more familiar with five of the many chemical reactions.

Molecular and polarity Shape Lab

Introduction:
We started with a Lewis diagram for the molecule. When there were more than two atoms,we focused on the central atom in the molecule. Count the number of atoms bonded to the central atom and count the number of unbonded pairs of electrons on the central atom and then determined the molecular shape correspondingly


CENTRAL ATOM MOLECULAR
Shape
Bonded Atoms Unbonded Electron Pairs
__________________________________________________
1 any number linear
2 none linear
2 1 or more angular
3 none flat triangular
3 1 triangular pyramid
4 none tetrahedral


Determining the polarity of the molecule requires an additional step. After determining the shape, look at whether the atoms surrounding the central atom are all identical to one another. Then we began making our figures.

Molecular Shape Molecular Polarity
_________________________________________________________________________________
linear yes nonpolar
no polar
angular - polar
flat triangular yes nonpolar
no polar
triangular pyramid - polar
tetrahedral yes nonpolar
no polar






WHICH STRUCTURE FROM THESE 4 PICTURES IS INCORRECT AND WHY? FEEL FREE TO POST YOUR ANSWER ON OUR COMMENTS





C6H12O6 was a structure we chose to use because of its ring structure or glucose ring. A basic sugar, this is a monosaccharide, a pentose sugar...

There are usually 3 common molecules of C6H12O6 that you will come across which are; Glucose, galactose and Fructose.

these molecules can combine to become di(2)saccharides such as maltose (2 Glucose') or Lactose which is the sugar in milk making it taste sweet.




A heavy gaseous hydrocarbon, C3H8,occurring naturally dissolved in crude petroleum, and also made artificially.
shape--octahedral
bond angle--90 degrees
polarity--yes
resonance--no




The chemical compound with the formula BF3. This colorless toxic gas forms white fumes in moist air. It is a useful Lewis acid and a versatile building block for other boron compounds.
shape--trigonal planer
bond angle--120
polarity--no
resonance--no



The organic compound with the formula C2H4. It is the simplest alkene. Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon.
shape--octahedral
bond angle--90-109.5 degrees
polarity--no
resonance--no



a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state.

shape--linear
bond angle--180 degrees
polarity--no
resonance--no

Conclusion:

Overall we accepted our hypothesis because we learned how to make the Lewis structure shapes by a hands on activity; allowing us to learn and see first hand what they will look like and how to build them.

We found out that by looking at the problem and fixing it hands on we were better capable of understanding and learning these concepts. We were always drawing structures and making shapes,we completely learned the polarity and molecular shapes and figures of this lab.