Lab Report 32

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Chemistry lab report
Experiment 32
Voltaic Cell Measurements

Dinmukhamed Yeraly
Partner Azamat Bashabayev
General Chemistry II lab
Instructor Rostislav Bukasov

Nazarbayev University

Introduction
Most of the chemical reactions can be classified as redox reactions, which include two half reactions, oxidation and reduction respectively. To measure the tendency for a readox reaction to occur, special apparatus called voltaic cell can be used. It is made by connecting a voltmeter between two electrodes, which are immersed in to the two different solutions separated by porous barrier. This barrier allows flow of ions, so that the voltage or potential can be measured. In a closer look of such reactions, it can be determined that the sum of the potentials of oxidation and reduction is actually the voltage of the whole voltaic cell. For convenience negative electrode of the voltaic cell is considered to be that where oxidation occurs – anode, and it is connected to the negative pole of electrode. The picture bellow is a schematic diagram of the voltaic cell which we will study. However this also makes trouble in calculating individual potentials of reduction or oxidation. For this reason Hydrogen standard electrode is used. Its value is assigned to be 0 V, so that measuring it with any other substance can give approximate value of potential. Concentration also significantly affects the cell potential. The aim of this experiment was to learn how to determine the cell potential in a voltaic cell. We also will learn about the concentration and temperature effect on the cell potential

Materials

Cu2+| Cu| Fe2+|
Fe3+| Graphite| Br2(l)|
Br| C| Cl2|
Cl-| I2(s)| I-|
Zn2+| Zn(s)| DI water|
Digital multimeter| Graduated Cylinder| Beakers|
Cable clips| Glass crucible| Wash bottle|
Safety goggles| Lab coat| |

Discussion

In Part A all of the seven cells were made up well and the cell potential of each of them were...
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