amount of electricity that passesthrough the system. This relationshipis shown in the equation:C=Atwhere C is the amount of electricitypassing through the circuit, 1 coulumbbeing transported every second byeach ampere. A is the current inampere and t is time in seconds.96,500 Coulomb per mole of electronis equivalent to 1 Faraday, which is theelectrical charge contained in 1 moleelectron. Using this formula, theconcentration of the half-cell can becalculated and substituted to theNernst equation.The purpose of this experimentis to further understand and apply theconcepts of electrochemistry and theprocesses and elements of anelectrochemicalcelltoactualexperiments and to determine thespontaneity of reduction-oxidationreactions based on standard reductionpotential.Experimental DetailFor the first part of theexperiment, three half cells wereprepared, with cell notations of3
Subscribe to view the full document.
Cu2+(1M)|Cu,Zn2+(1M)|ZnandFe3+(1M),Fe2+(1M)|C.Thefirstelectrode was prepared by immersinga copper electrode in 1 M CuSO4. Thesecond half cell was prepared byimmersing a zinc electrode in 1 MZnSO4. Lastly the third half cell was amix of equal volumes of 2 M FeSO4and2 M FeCl3with graphite as itselectrode. An iron nail was not useddue to the side reaction that mightcause rust to form on the nail’ssurface:2+¿→FeO3+¿→ Fe¿Fe¿Instead, a graphite electrode, which isa semi-conductor, was used. This ismade of the electrically inert carbonthat would not participate in thereaction. These half cells were thenconnected with the wires of the volt-meter to a copper half cell prepared inthe same manner. A salt bridge wasmade out of rolled filter paper soakedin saturated potassium nitrate andthen each of its ends was soaked inone of the two half-cells. The set-upsfor the first part of the experiment isshown in Figure 2.Figure 2. Voltaic Cell Set-upFor the second part of theexperiment, another 3 half cells wereprepared with cell notations Cl-(1 M),Cl2| C, Br-(1 M), Br2| C, I-(1 M), I2| C.Like in the third half cell, a graphiteelectrode was used. Potassium halide(KX) solutions were electrolyzed byimmersing two graphite electrodesinto the solution and connecting theseto a 1.5 V dry cell which serves as itsenergy source as shown in Figure 3.This was done for 1 minute, until thehalide ions were oxidized to halogens,X2. Figure 3. Electrolytic Cell Set-upThepreparedmixtureofhalogens and halide solutions werethen connected to the copper half-celllike the set-up in Figure 2. The volt-meter reading for thesix voltaic cells prepared wererecorded and used in calculations.Results and DiscussionThe measured voltages of theprepared voltaic cells are tabulated inTable 1. Table 1. Volt-meter ReadingsSet-up #CellNotationVolts1Cu|Cu2+||Cu2+|Cu0.08962Zn|Zn2+||Cu2+|Cu1.083Cu|Cu2+||Fe3+|Fe0.4144C|Cl-,Cl2||Cu2+|Cu0.4685C|Br-,Br2||Cu2+|Cu0.2696C|I-,I2||Cu2+|Cu0.1214X-bat
The potentials measured fromthe experiment are the potentials ofthe whole voltaic cell set-ups while thegiven potential of the referenceelectrode, Cu2+/Cu, is 0.34 volts. From
As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.
Temple University Fox School of Business ‘17, Course Hero Intern
I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.
University of Pennsylvania ‘17, Course Hero Intern
The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.
Tulane University ‘16, Course Hero Intern
Ask Expert Tutors
You can ask 0 bonus questions
You can ask 0 questions (0 expire soon)
You can ask 0 questions
(will expire )