Robin N. Tomczak
Partner: Jackie Weisberg
Rntomczak81@gmail.com
February 24, 2015
CHM151-AC61

Stoichiometry of Reaction of Iron with Copper (II) Sulfate Solution

Objective To demonstrate the use of stoichiometric principles in order to verify the correct chemical equation of the reaction between iron metal and a solution of copper (II) sulfate.

Theory Stoichiometry is a branch of chemistry which deals directly with the law of definite proportions and also the conservation of mass and energy to chemical activity. In the experiment the reaction between iron metal and copper (II) sulfate is analyzed. The reaction produces a fine dark powder, which is copper metal. This type of reaction is known as a single displacement reaction. This occurs because iron is known to be a more active metal than copper. In order to become copper atoms, the Cu+2 ions must gain electrons. The process in which an atom gains electrons is known as reduction. When a single displacement reaction occurs, the more active metal is the source of these added electrons. This more active metal therefore undergoes oxidation, or the loss of electrons. So, during our experiment the copper is reduced and the iron is oxidized. Iron forms two types of ions, which are Fe+2 and Fe+3. Stoichiometric principles are used in order to determine which of these two ions are produced during the reaction between iron and copper (II) sulfate solution. If Fe+2 is formed, then the following equation (1.) is correct:
1.) Fe(s) + Cu+2(aq) → Fe+2(aq) + Cu(s)
If Fe+3 is formed, then this following equation (2.) is correct:
2.) 2Fe(s) + 3Cu+2(aq) → 2Fe+3(aq) + 3Cu(s)
During the experiment, copper (II) sulfate is added to a known amount of iron. The amount is known, because it will be weighed before the reaction. After the reaction takes place, the amount of copper produced is then weighed as well. These weights can be used to calculate the mole-to- mole ratio of iron to copper. If equation 1 is correct, the Fe:Cu mole-to-mole ratio is equal or 1:1. If equation 2 is correct, then the Fe:Cu mole-to-mole ratio would be that of 3:2.

Procedure
Refer to CHM151 lab manual

Data Grams of Iron Used
Trial 1
1.006g
Trial 2
1.001g

Beaker Mass (in grams)

Initial mass before reaction
Final mass after reaction
Trial 1
116.938g
118.019g
Trial 2
63.948g
65.146g

Data Analysis
Equation #1 moles of Cu+2 calculation:
1.0g Fe x 1 mol Fe__ x _1 mol Cu_ =