4. Discussion
4.1 Key findings
4.1.1 Key findings for Experiment 1
The voltage across the Leyden Jar increases with the amount of salt put into the jar.
4.1.2 Key findings for experiment 2
The voltage across the Leyden Jar decreases in inverse proportion with the breadth of the foil.
4.2 Explanation of key findings
4.2.1 Explanation of key findings for Experiment 1
We found that the more salt we put into the water, the higher amount of short circuit voltage the jar can store. This is because the salt increases the conductivity of the water, as when salt is added to the water, the salt molecules split into two different ions, a sodium ion and a chlorine ion. The sodium ion is missing an electron, which gives it a positive charge, but the chlorine ion has one extra electron, giving it a negative charge. As such, an electric source sending a current through water will have two terminals: a negative one that conducts electrons into the water, and a positive one that removes them. Since opposite charges attract, the sodium ions are attracted to the negative terminal, and the chlorine to the positive terminal. The ions form a bridge, the sodium ions absorbing electrons from the negative terminal, passing them to chlorine ions and then the positive terminal. Thus, salt water is conductive, and the more salt you put in, the more conductive the water is. (National Aeronautics and Space Administration)
4.2.2 Explanation of key findings for Experiment 2
We found that curiously, against our expectations, that an increase in the area of the foil-wrapped outer side had a negative effect on the storable voltage. We suspect that this is because of improper setup of our experiment, as it is documented in other sources about Leyden Jars that the bigger the area of the foil, the greater the amount of short circuit voltage that can be stored. (National High Magnetic Field Laboratory, 2003)
4.3 Evaluation of hypotheses
4.3.1 Evaluation of hypothesis(1)
We were right with our hypothesis:
The greater the concentration of salt, the greater the amount of short circuit voltage storable by the Leyden Jar.
4.3.4 Evaluation of hypothesis(2)
Our hypothesis was wrong, the greater the outside area of the jar covered with foil, the less electricity could be stored. We suspect this could be because of improper setup of the jar.
4.4 Areas for improvement
4.4.1 Data Collection
We should have done more experiments within the time limit that was given to us so that we could test more variables and collected more data.
4.4.2 Instruments
We could have gotten a better stirrer so as to mix the salt water better. We should have learned to read the multimeter before we got it as we were stuck on how to use the multimeter at the beginning, thus making us lose some time.
4.4.3 Scope
Our planned scope at the beginning of the experiment was too broad and more focused on the idea of storing lightning than concentrating on the exact factors affecting storage of the leyden jars.
4.4.4 Method
We were slow in writing down the proper procedures for our experiments, thus we had to redo some of our experiments because we forgot about 1-2 steps. If we had gotten down the proper procedures earlier on, we would have had more time for other experiments.
4.4.5 Analysis of Results
We could have done a lot more research on the results. One of our experiment’s results was totally different from what we expected and we could have researched more into why the results are different.
