Conclusion

The purpose of this experiment was to determine which metal (aluminum, steel, or copper) produces the highest rate of hydrogen and oxygen gas through electrolysis. Electrolysis was used to use the gases produced to be able to lift a pontoon. The cell was made up of a single metal that acted as both the anode and cathode. Each metal was placed in a 0.6 M salt water solution and electrolysis took place in an airtight container where hydrogen and oxygen were created then collected in a graduated cylinder to be measured in milliliters. It was hypothesized that aluminum would yield the highest rate of gas production measured in milliliters per minute. This hypothesis was rejected after it was found that steel produced the highest rate of gas production. This was determined because steel had the highest overall average rate of gas production and the highest rate of gas produced without the trial being an outlier. Steel also was the only metal to not produce zero milliliters in a trial; both copper and aluminum had a trial or multiple trials that produced no gas. It also tested which metal performed closest to its theoretical yield. An ANOVA and a percent yield test were both conducted. An ANOVA test was conducted to confirm if any of the metals had similar mean gas production rates. The hypothesis tested was if the mean steel rate of gas production, mean copper rate of gas production, and mean aluminum rate of gas production was equal. H_o was equal to the hypothesis that all the means were equal. H_a was equal to the hypothesis that all the metals means were not equal. The results showed that H_o was rejected at an alpha level of 0.01 meaning all the metals means were not equal. It was highly unlikely to obtain these results again by chance alone. The percent error test found that steel had the lowest percent error at 40.51% rate of gas production from the theoretical yield. The gas that was predicted was the hydrogen, oxygen, and hydroxide gas. This means that steel performed the closest to what the theoretical yield of rate of gas production was. However, 40.51% is still a high percent error meaning although steel was the most efficient metal, steel did not produce nearly as much gas as it was expected to.

On the surface, steel performed efficiently for two reasons. Steel was able to resist corrosion better than the other metals, still able to efficiently produce gas. Steel is mostly consisted of iron. This means the element iron can act better as both an anode and a cathode on the standard reduction potential table compared to the elements copper and aluminum. While copper acts as a better cathode since copper is a better oxidizing agent, it works worse as an anode since copper is a poor reducing agent. The opposite effect happens with aluminum; out of all three metals aluminum is the best reducing agent but the worst oxidizing agent, so it works well as an anode but works poorly as a cathode. Steel or iron is somewhere in between these two metals in terms of standard reduction potential so there is a good balance of the metal acting as an anode and cathode. Also, steel was able to still allow electrical current to flow despite the rust it produced compared to the other metals. Electrolysis on an atomic level can also explain what is happening and why steel preformed the best. Since the molarity of the salt water solution stayed constant with all the trials the only thing to look at is the structure of the metals themselves. Steels electrons were able to flow through the metals, current, and electrolyte with more ease than copper or aluminum allowing for faster rate of production.

When conducting further research, there are a variety of factors or issues that could be changed or fixed. The first main issue in this research would be inaccuracies in equipment and data collection. Due to a limited budget and limited supplies, the setup may have errors or faults that were not noticeable during trials. The electrolytic cells were constructed by hand using basic hardware from a local hardware store that may not have been the best choice for this experiment. Also, the metal of this hardware did not match the metal of the plates; the hardware was made of stainless steel which reacts differently than copper, aluminum, and steel. One idea for improvement is to match the metal of the sheets to the metal of the hardware. Another issue to address would be a more precise way of measuring the volume of gas. With the precision of the graduated cylinder and the fact that it is measured by eye and recorded by placing a data point on a laptop screen, there is a lot of room for errors or inaccuracies to occur. A larger budget with more precise instruments will highly benefit this experiment. Also, the actual factors of this experiment can be changed. Further research can explore different types of metal or different sizes and shapes. This will change the surface area and distance between the plates which may have effect the circuit and, in turn, the rate of production of gas. Due to the purpose of this experiment, the molarity of the solution matched that of a real ocean, but further research could also change the molarity of the solution. This research will expand the overall knowledge of electrolysis and the effect of different factors. If the metals and the solution change to different materials, then electrolysis can be used to produce different gases therefore expanding the uses and applications of the process of electrolysis.