WHY SCIENCE is committed to encouraging excellence in all areas of STEM fields. One such area is sustaining long term student interest and engagement in science. To that end, WHY SCIENCE will be sharing science achievement stories, written by students, with you. The first story in this series, “Greener World”, is written by Sean Hackett, a 7th Grade Connecticut State Science Fair finalist from E.C. Adams Middle School. Let’s encourage broader support for our high achieving students by celebrating their success. Enjoy!
For my science fair project, I studied the effect of salt on the amount of hydrogen produced by the electrolysis of water. I chose this project because I have always been interested in making the world a greener place and in creating more efficient ways to protect and preserve the environment. For example, I have played an active and important role in the recycling program in my town. When I was in the third grade, I took note of the numerous reusable materials that were being thrown out instead of recycled at my elementary school. Therefore, I met with the school principal and established a recycling system that is now standard for all of the schools in my town. Moreover, to apply my science fair project towards making the world a greener place, I thought about how fossil fuels are a common source of energy for humans around the world.
The problem with fossil fuels is that, not only are they slowly running out, they also produce harmful emissions that endanger the state of the environment. For instance, if the current level of usage of natural gas remains, then the earth will run out of this fossil fuel within the next fifty years. This is where hydrogen comes into play. Hydrogen can be used in fuel cells to power a number of things (including passenger vehicles), and produces no harmful emissions whatsoever. However, although it is the most abundant gas in the universe, hydrogen is rarely found in a free state. Therefore, in order to obtain hydrogen, it must be separated from a chemical compound. If an effective way to obtain hydrogen is found, it could essentially replace harmful fossil fuels as a source of energy. One chemical compound that consists of hydrogen is watr (H2O), which is comprised of two hydrogen atoms and one oxygen atom. To generate hydrogen from the water, the process of electrolysis must be used. The electrolysis of water is the decomposition of water into oxygen and hydrogen gas due to an electric current being passed through the water. To increase the amount of hydrogen produced by the electrolysis of water in order to make it a more effective and economical source of hydrogen, my science fair project tested to see if salt increased the hydrogen production. I hypothesized that the salt would increase the amount of hydrogen produced by the electrolysis of water because salt water is an electrolyte solution while distilled water is free of salts, thus a very poor conductor of electricity. As a result, the electrical current would transfer through the salt water more quickly than through the distilled water.
In order to test this theory, I electrolyzed both salt water and distilled water, and then compared the amount of hydrogen produced by both solutions to determine if the salt did in fact increase the amount of hydrogen produced by the electrolysis of water. The procedure I followed began by first wrapping copper wires around the cathode and anode of a 9-volt battery, and then bending the wires so that they arced into a beaker filled with a salt water solution (90% distilled water, 10% sea salt). After doing so, I filled a test tube with the same concentration of salt water and then calculated the volume of the salt water. Then, while sealing the opening of the test tube with a quarter, in order to contain the salt water, I flipped the test tube upside down and inserted it into the salt water of the beaker directly above the end of the copper wire that was connected to the cathode of the battery (where the hydrogen was being produced). Afterward, I held the test tube in place above the wire so that the hydrogen being produced would bubble up into the test tube, therefore displacing the salt water. After four minutes of this, I again sealed the opening of the test tube with a quarter and removed the test tube from the water. I then calculated the volume of salt water that was now in the test tube and found the difference between the amount of salt water in the test tube before the water was electrolyzed, and after the water was electrolyzed. The difference represented the amount of hydrogen produced in the four minutes that the salt water was electrolyzed. I repeated this process for four trials to have sufficient data, and then an additional five times using distilled water as opposed to salt water.
There were few problems overall with my science fair project. One problem was that during experimentation, not all of the hydrogen produced may have been collected in the test tube. This would have caused the results of my experiment to show that there was less hydrogen produced than there actually was. However, I do not think that this issue would have affected the results of my experiment very much because the test tube was held directly above the end of the copper wire that was connected to the cathode of the battery; therefore, the hydrogen being produced most likely flowed up into the test tube. In addition, the opening in the test tube that the hydrogen passed through was very large; consequently, it is very unlikely that any hydrogen would have escaped. Lastly, the hydrogen being produced could be seen traveling from the end of the copper and up into the test tube, and I did not observe any hydrogen that did not travel into the test tube. Another problem was that during experimentation, the quarter might not have completely sealed the opening in the test tube. Therefore, hydrogen that was in the test tube may have escaped, or water from the beaker may have entered it during a trial. This would have resulted in the amount of hydrogen produced being a little less than the actual amount of hydrogen produced. A third problem with my science fair project was that if salt water were to be electrolyzed in fuel cells, it could cause the fuel cells to corrode. For that reason, the fuel cells would have to be treated or made of special materials, which would make the fuel cells too expensive and, as a result, make the process of using salt water instead of distilled water too impractical. However, if a cost-effective way to keep the fuel cells from corroding were found, then using salt water instead of distilled water would be beneficial.
As for my future in the field of science, I am not sure as to what I will do. However, I do know that I want to continue my studies of science and mathematics all through college, and eventually apply my skills towards solving science-related issues throughout the world. I think that the science fair has been a great experience and has opened the doors of science for me by showing me just how interesting and exciting it can be. I hope that I will be fortunate enough to take part in the science fair next year.
For Sean’s science fair abstract “The Effect of Salt on the Amount of Hydrogen Produced by the Electrolysis of Water” see page see Project Number 5028 on page 257 of this document at http://www.ctsciencefair.org/documents/Abstracts2011.pdf