There are five types of reactions: synthesis, single displacement, double displacement, decomposition, and combustion. The first reaction, synthesis, is a chemical reaction in which atoms or simple molecule combine to form one single compound. In a single displacement reaction, one element replaces another element in a compound that is in a solution. A double displacement reaction is when ions from two compounds interact in a solution to form a product. Combustion is a violently exothermic reaction with oxygen to form oxides. Decomposition is when a single compound is broken down to produce two or more simpler substances. Lastly, a combustion reaction is an exothermic reaction, usually with oxygen, that forms oxides. It also forms CO2 and H2O.
Materials:
- 3 test tubes
- test tube rack
- CuSO4 solution
- Ba(NO3)2 solution
- HCL solution
- H2O2 solution
- MnO2
- Bunsen burner
- Zinc
- Magnesium ribbon
Since we were once again working with potentially dangerous chemicals we took safety precautions and put on goggles and lab aprons before we started any of our work. We then took our first test tube placed a piece of zinc in the bottom and added about 1/2 mL CuSO4 solution. Next, we took our second test tube and added about 1/2 mL Ba(NO3)2 solution to about 1/2 mL of CuSO4 solution. In our third test tube we placed a piece of magnesium ribbon and added about 1/2 mL of HCL solution. During each of these reactions we recorded our observations in our journals. After this we lit a bunsen burner (burning propane gas) and recorded our observations of the flame. Next, we rinsed out the first test tube and added about 1/2 mL of H2O2 solution and lightly heated it over the flame. We recorded our observations of this reaction as well. Then we added a pinch of MnO2 (catalyst) to the H2O2 and lightly heated it to watch the reaction again. Then we recorded our observations one final time. Once we were done cleaning up our equipment and putting it away we made up a data table to show our results. We also identified what reactions took place and wrote out the balanced equations of each.
Discussion:
How do we know that the reactions that occurred were chemical reactions?
Reaction 1: In this reaction between CuSo4 and Zn, the zinc changed color from
Silver into a reddish, copper color, an outcome of chemical reactions. This reaction
Is an example of a single displacement reaction as shown in the balanced formula-
Zn+CuSo4>Cu+ZnSo4.Reaction 2: In this second reaction between Ba(No3)2 solution and CuSo4, the
Mixture bubbled, a precipitate formed on the bottom of the tube, and it also changed
Color a sign of a chemical reaction. This reaction is an example of a double displacement- Ba(No3)2+CuSo4>BaSo4+Cu(No3)2
Reaction 3: In this reaction between Magnesium Ribbon and HCl solution, the
Mixture began to fizz and turned into a gray color. This reaction is an example of
A single displacement reaction-Mg+2HCl>H2+MgCl2.
Reaction 4: In this reaction with lighting the Bunsen burner, and the form
of a flame, it gave off heat and was a blue and orange color. This reaction
Is an example of a combustion reaction-C3HS+5O2>3Co2+4H2O.Reaction 5: In this reaction we put a tube of H2O over a flame, it fizzed and oxygen
Bubbles rose to the surface. This reaction is an example of a decomposition reaction-
2H2O2>2H2O+O2
Conclusions:
We found that though there are five reactions only four occurred in our experiment. In our five reactions synthesis never took place because none of the reactions consisted of two elements/compounds reacting together and forming one compound. Our first and third reaction were both single displacement reactions. As we know from the introduction single displacement means that one element replaced another element in a compound as we can see in the equations in the data table. The second reaction in our experiment was double displacement because elements from two compounds switched places. In this reaction there were bubbles and a precipitate was formed. You can see this in our data table as well. The fourth reaction was combustion because it was an exothermic reaction that produced oxides. We knew that this reaction was exothermic because the test tube was hot while the reaction was taking place and there were sparks. The last reaction was decomposition because one compound broke down into two simpler compounds. Some of our observations from this reaction was steam and bubbles.
