Zixuan Huang
PART.1
Purpose
To explain the chemical reaction between copper (II) chloride and iron.
PART.2
Materials
Nail
Jar
Steel wool
Electronic scale
Laboratory sealing film
Diagram
Chemicals
Procedures
Observation and Data collection
Obersvation：After putting the nail into copper(II) chloride, Fe and CuCl2 chemically react to double replacement, and finally the copper forms a brown cluster around the nail.Finally, the water in copper evaporates.The solvent color change from blue to yellow.
The first day
The second day
The third day
Data Collection:
Data Analysis:
Measure the amount of copper and copper(II) chloride to get their chemical equation:
final - initial = chemical that participates in the chemical reaction
weight s of Fe: 9.95-9.78=-0.17g ( been used)
weight of copper: 76.77-76.99=0.22g (been form)
Fe: 9.95-9.78=-0.17g
Cu: 76.77-76.99=0.22g
Mass / volume = molarity * molar mass
100ml=0.1L
0.1L=0.5molar mass
Molar mass:0.1/0.5=0.2 mole
Fe + CuCl2 → FeCl2 + Cu
1)Determine limiting reactant and excess reactant
Fe:0.17g Fe x 1 mole Fe/55.845g Fe ➗ 1 = 0.003= 3 x 10^-3 LR
CuCl2:0.2 mole CuCl2 ➗1 =0.2 ER
0.0030 mol Fe x 1 mole Cu/ 1 mole Fe x 63.546g Cu/ 1 mol Cu= 0.2g Cu
2Fe + 3CuCl2 → 2FeCl3 + 3Cu
Fe:0.17g Fe x 1 mole Fe/55.845g Fe ➗ 2 = 0.002 LR
CuCl2:0.2 mole CuCl2 ➗ 3 =0.067 ER
0.0030 mol Fe x 3 mole Cu/ 2 mol Fe x 63.546g Cu/ 1 mol Cu= 0.3g Cu
2)Calculate the % yield of Cu
Fe(s)+ CuCl2(aq→ FeCl2(aq)+ Cu(s)
%yield = (actual yield/theoretical yield) x 100
110% = (0.22/0.2)x100
2Fe(s)+ 3CuCl2(aq)→ 2FeCl3(aq)+ 3Cu(s)
%yield = (actual yield/theoretical yield) x 100
73.3% = (0.22/0.3)x100
Result: The data of the first equation is close to the product that we got, therefore the second equation is the actual chemical equation.
3)Calculate the # of Cu atoms in your product sample
1 mole = 6.02 x 10^23 atoms
1 mole = 6.02 x1023atoms
0.22g Cu x 1 mole/ 63.546g Cu x 6.02 x 1023Cu atoms = 2 x 102atoms Cu
4)Write the balanced redox ½ rxns
Fe(s)+ CuCl2(aq→ FeCl2(aq)+ Cu(s)
Reduction
Cu2++ 2e− → Cu
Oxidation
Fe→ Fe2++ 2e−
Complete Equation: Cu2+(aq) +2Cl1-(aq) + Fe(s)→ Cu (s)+ Fe2+(aq)+ 2Cl1-(aq)-
Ionic Equation: Cu2+(aq) + Fe(s)→ Cu (s)+ Fe2+(aq)
Particle diagram
Discussion
The purpose of this lab is using the single replacement that happens between Fe and Copper II chloride to figure out the actual chemical equation of the reaction that occurs in this lab. Because the Copper inside the solvent that is unknown for it is +2 charge or +3 charge. So people can say that a less reactive element can be replaced by a more reactive element in a compound to determine the chemical equation.
For doing the calculation of the stoichiometry to figure out the chemical equation, record the data of Fe has been used and amount of the Copper II has been formed are the requirements. There are a few precautions still to be reminded in this lab. The first nail is easy to rust. Before we conduct the experiment, we must ensure that there is only Fe on the nail, otherwise the contact area between Fe and Copper II chloride will affect the efficiency of the chemical reaction between them. The second point is also the one that is most easily overlooked. After we take out the nail that has chemically reacted with copperII chloride, no matter how carefully and smoothly we take it out, it will shake in the process, which leads to the fusion of the copper molecule and the solvent. The possibility exists, so after we take out the nail, it is best to let it sit for a period of time to allow the copper to completely settle before measuring is the best way to ensure the accuracy of the experiment.
Stoichiometry is the main theory used to find the correct chemical equation. It expresses the relationship between the relative amounts of substances participating in a reaction or forming a compound.After we have written two chemical formulas that may occur （Fe(s) + CuCl2(aq → FeCl2(aq) + Cu(s) and 2Fe + 3CuCl2 → 2FeCl3 + 3Cu), we need to apply stoichiometry to determine which chemical equation actually occurs. We use the collected data to find out that Fe is a limiting reactant, and then use it to figure out how much Cu formed after reaction, and then use two chemical equations to get the theoretical amount of Cu that will be form and compare to the actual Cu formed in our lab, we can know that the Cu quantity calculated by Fe(s) + CuCl2(aq → FeCl2(aq) + Cu(s)is the most similar to the experimental result, we can know that this is the correct chemical equation.
Redox reaction is a chemical reaction in which the oxidation number of elements has corresponding rise and fall changes before and after the reaction. This reaction can be understood as consisting of two half-reactions, namely oxidation reaction and reduction reaction. Such reactions obey the conservation of charge.Redox reactions have four categories that belong to it, they are single replacement, synthesis, decomposition and combustion. The exact name of what kind of is single replacement redox reaction.
Error Analysis
approximated value: 0.22g Cu
exact value: 0.2g Cu
0.22-0.2/0.2 x 100 =9.1%
Error 1: Did not wait for the solvent to completely dry out when measuring Copper II precipitation.
Propagation: Because of there still have some solvent mix inside the copper II precipitation, which leads to copper II measuring weight higher than the actual weight, because there is only one day to let it air dry, if it is naturally air-dried, the time is not enough, so in order to avoid this error, we It’s best to turn on the fan, let it be in an environment with flowing wind.
Error 2:When taking out the nail and separating the copper attach on it, use the nail to stir in the solvent.
Propagation: Stirring in the solvent with nails caused a small part of the copper molecules to break away from the precipitation group and mix with the solvent, so some copper molecules were poured out together with the solvent, which resulted in a reduction in the actual weight of the copper. In order to avoid this error, we When taking out the nail, it is best to rinse the copper on it with water instead of stirring it, and then filter it with a filter when pouring out the solvent.
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