# A lab of Reduction/Oxidation Reactions

Essay by pisces_009High School, 10th grade May 2004

Title: Redox Reactions

Research Question: Is it possible to determine if a redox reaction took place by using only the equation?

Hypothesis: Yes, I believe it is possible to determine if this reaction took place by using the oxidation numbers in the equation.

Variables:

1. I cleaned the reaction surface to limit contamination

2. I held the chemicals at approximately a 90 degree angle for consistency

Introduction:

Redox reactions occur when both oxidation and reduction take place. All atoms can be assigned an oxidation number, which is a positive or negative number that help in determining the reducing and/or oxidizing agents in an equation. An increase in the oxidation number of an atom from one side of an equation to another side indicates oxidation. A decrease in the oxidation number of an atom indicates reduction. For example:

2AgNO3 + Cu Cu(NO3)2 + 2Ag

In this equation, on the left side of the equation the Ag has an oxidation number of silver is +1 and on the other side the Ag oxidation number is 0.

Since the silver ions decrease in oxidation number, reduction is occurring. Similarly on the left hand of the equation the Cu has an oxidation number of 0 and on the side it has an oxidation number of +2. Since the copper ions increase in oxidation number, oxidation is taking place.

Materials:

1. Reaction surface

2. Chemicals

a. Cl2, KMnO4, H2O2, KIO3, K2Cr2O7, NaNO2, CuSO4, FeCl3, KI, starch, HCl, NaHSO3, Na2S2O3

3. Pipette for stirring chemicals in reaction

4. Pencil and paper

5. Safety goggles*

Procedure:

1. Make a chart to record collected data from the experiment

2. Gather all necessary chemicals and other materials

3. Mix one drop of KI with one drop of NaOCl and observe if a reaction takes place

4. If no reaction...