Abstract
Electrolysis is a method of using a direct electric current to drive an otherwise non-spontaneous chemical reaction. During electrolysis, hydrogen atoms (H2) are reduced at the cathode whereas the oxygen atoms (O2) are oxidized at the anode. There were three different solutions used in the experiment in order to have a better understanding of electrolysis reactions. From each solution, reaction equations were produced. The reactions could be observed from the indicators used. The reactions showed that hydrogen ions were produced at the anode, making it acidic and hydroxide ions were produced at the cathode, making it basic. In all parts of the experiment, the reaction that took place at the anode was 2H2O(l) O2(g) + …show more content…
When the current passes through, the water was oxidized at the anode and reduced at the cathode. The equations that were produced show that hydrogen ions are produced at the anode, making it acidic and hydroxide ions were produced at the cathode, making it basic. Sodium sulfate was used because pure water doesn't contain a high enough concentration of ions to produce a current; therefore, the sodium sulfate was acting as the salt bridge in the reaction. This processes was demonstrated in parts B and C as well; however, instead of the sodium sulfate acting as the salt bridge, potassium iodide was substituted in part B and potassium chloride in part C.
In each part of the procedure a different indicator was used – part A was accompanied by a universal indicator, part B was joined with phenolphthalein, and part C was combined with bromothymol blue. The indicators allow one to follow what was happening during the reaction. The indicator would change the color based on how acidic or basic the solution was. From the pH values obtained, one can then decipher the reactions taking place at the cathode and anode.