Experiment 2: Potential of a Galvanic Cell

I. AbstractA Galvanic cell is an electric cell that generates an electromotive force by conversion of chemical to electrical energy. It derives electrical energy from redox reactions; spontaneous redox reactions create electrical energy. This is where electrons from the reaction transfer through an external path or circuit. The Galvanic cell consists of two different metals connected by a salt bridge, separated by a porous disk or salt bridge. Galvanic cells are typically used as a source of electrical power, they produce direct current. Parallel-connected galvanic cells make up a battery.In this experiment, the researchers are expected to determine the electrode potential of a galvanic cell. The researchers need to construct a galvanic cell and determine the electrode potential with the use of a multi-meter. The setup must yield a positive reading. If not, there must be a problem with the construction the execution of the experiment of galvanic cell or. Also, the voltage reading must be accurate with the voltage readings on the Table for Standard Electrode potential.

II. Objectives The objective of the experiment is to construct a galvanic cell and determine its potential.

III. Procedure

1.) To start the experiment, the galvanic cell must be prepared. Two (2) test electrodes will be coupled. Each group will be given a half cell electrode; groups will pair up with another group. Use alligator wires to couple the half-cell electrodes, Make sure that the alligator wires do not touch the solution when the dipping the electrodes in the solution. Dip the ends of the salt bridge on each cell.2.) Set the multi-meter to voltage mode. Connect each electrode top the input terminals of the multi-meter and record the voltage reading. If you are getting/ reading a negative voltage, interchange the terminal connections. a.) Setup:

b.) Materialsa. Digital Multimeterb. 25-ml beaker (2pcs)c. Salt bridge: prepared by dipping a 1cm by 15cm filter paper in a saturated KCl solutionc.) Chemicalsa. Zn metal, 0.1M ZnSO4 20mlb. Pb metal, 0.1 M Pb(NO3)2 20mlc. Cu metal, 0.1M CuSO4d. Al metal, 0.1M Al(NO3)3

IV. Treatment of Resultsa. Write the Cell Diagram [2] for each cell measured, placing the negative electrode (anode) on the left and the positive electrode (cathode) on the right. Below the diagram write the electrode reactions and the overall cell reaction.

Cell Diagram: Al|Al3+ (1M) ||Pb2+ (1M) |PbElectrode reactions: Anode: Al Al3+ + 3eCathode: Pb2+ + 2e PbOverall cell reaction: 2Al + 3Pb2+ 2Al3+ + 3Pb

Couple (M1/M1+)---(M2/M2+)Measured Potential/ VStandard ElectrodePotential

1Zn/Zn2+Cu/Cu2+1.027V1.10V

2Zn/Zn2+Al/Al3+0.980V0.90V

3Cu/Cu2+Pb/Pb2+0.043V0.47V

4Zn/Zn2+Pb/Pb2+0.867V0.63V

5Cu/Cu2+Al/+Al3+0.034V2.00V

6Al/Al3+Pb/Pb2+0.109V1.53V

b. Compare the readings obtained in the different cells with the voltages expected based on the Table for Standard Electrode Potential.

V. Questionsa. What does a negative potential reading in the multi-meter indicate?A negative potential reading means that there must be a problem with the construction the execution of the experiment of galvanic cell.

b. Give some practical applications of electrochemical cells.Some practical applications of electrochemical cells are the storage and conversion of energy. Devices that carry out these conversions are called Batteries. Batteries are sets of galvanic cells that are connected in parallel.

VI. Conclusion and RecommendationGalvanic cells are only one of the million inventions made by man to improve life. These cells are important because they are the basis for the batteries that fuel modern society. Batteries are capable of delivering enough energy to power devices and machines. For the future researchers who will undertake similar research, the researchers would like to recommend the following: Production of more cells to be able to create batteries that consist of parallel galvanic cells Conduct more trials for the accuracy and precision of data gathered.