CynthiaKimberLarissa

=**Battery Challenge (Part 2)- Temperature**= By Cynthia, Kimber, Larissa

__Introduction:__
The purpose of this experiment was to test a variable and see how we could use it to make a battery better and more efficient.Simplicity was important in this experiment, because the less variables there are, the less chance there is for error.

__Independent Variable__: Temperature of water __Dependant Variable__: concentration of salt, size of electrodes, amount of water, temperature of air (room temperature)

__Expectations/Hypothesis__: If the water is cold then the current will be lower because the electrons will be moving slower. If the water is hot then the current will be higher because the electrons will be moving faster.

__Mathematical Equation:__ y=mx+b, or I=mT+0 I=current, T=temperature and b=0 amps, if we are in degrees Celsius.

__Materials:__ hot pad, salt, water, 1 beaker, alligator clips, metals (copper+aluminum), ice, thermometer, stirring stick, a big bowl, voltmeter

__Procedure:__
1) Partially fill a big bowl of ice cubes to chill the water. 2) Fill 1 beaker with 100mL of salt water (salt water=20mL of salt mixed with 500mL of water) 3) Put the beaker into the bowl of ice and insert a thermometer 4) Chill the beaker of salt water by refrigerating. Check the temperature of the water every few minutes. Remove after the temperature has reached 0 degrees Celsius. 5) Put the two metals into the beaker. Make sure they don't touch. 6) Measure the volts and current by clipping one wire to one metal, and one wire to another. Then clip both wires onto a wire on the voltmeter, and record the volts and current. 7) Fill in the chart. 8) Put the beaker on a hot pad. With a hot pad, raise the temperature in intervals of 20 degrees Celsius (20, 40 etc.). Check with thermometer to make sure that the water is the same temperature. 9) Test the voltage and current each time, and fill in the chart.

//Diagram: This is what our experiment looked like when we collected most of our data.//

__Data:__
//This is a table of all of the data we collected during our experiment.//

Evaluation on the Experiment By: Larissa The purpose of the experiment was to test a variable and see how if would affect a battery and to see what would make the battery stronger. My group picked the temperature of the water as the variable that we would change, it is the Independent variable. The Dependant Variables would be the concentration of salt, size of electrodes, amount of water, and temperature of air (room temperature). The materials we used were a hot pad, salt water, beakers, alligator clips, metals (copper and aluminum), ice, thermometer, stirring stick, a big bowl, and a voltmeter. So we think that this will show how the current will pass through cold and hot water and the water temperature in-between. To see that if I were to make my own battery I would know what would make my battery stronger and what would make it weaker. This would also help me get a better feel of how electrons move around. Before we did the experiment I made my hypothesis. It was that if the water is hot then the current will be high because the electrons will be move faster and if the water is cold then the current will be lower because the electrons will be move slower and. I made this hypothesis with my pervious knowledge of electrons and current. I also made an educated guess from the knowledge I already learned. My group and I came up with this hypothesis together because we thought that it made the most senses. After we did the experiment I found out that my hypothesis was correct. The current was lower in the cold water and the current in the hot water was higher. As you can see in the graph the warmer that water became the higher the current went. This then proved that my hypothesis for what would happen was correct. There for there is nothing I would have to change in my hypothesis to make it correct because it was all correct and the graph shows that it is correct. So if you want to make a battery you should put it in a cup of hot water instead of cold water to get a better current. This is an import fact to understand because it teaches you a lot about electrons and current. If I were to make a big battery with the knowledge I learned in this experiment to make it work effectively. When I make my battery I would make sure that I would make sure that my salt was hot so that it has a better current that flows through the wires to light up the light bulb or what ever you are trying to power. This would work because the electrons in all the cups and in the wires are speeding up because the water is hot so they become jumpy unlike if they were in cold water then they slow down. So that is why I would add hot water because I would want my battery as strong as it could be. The other factors would also have an effect on the current. Such as the solubility level in the water, and the size of the metals. Even though there are these factors I think that temperature is the most important if you want to make you battery very powerful and for it to have a very strong current.

Battery Experiment Evaluation By: Kimber For this experiment we were to test the different variables related to creating a battery out of salt water and two different types of metal, copper and another metal. My group chose to test whether the temperature of the salt water in which the metals were sitting in changed the amount of current the battery produced. To do this we chilled our salt solution to zero degrees Celsius and then tested the current and voltage. We then raised the temperature every twenty degrees and repeated the same experiment. We predicted that it the salt water is cold the current will be lower because the electrodes will move slower and if the water it hot the current will be higher because the electrodes will be moving faster. We also hypothesized that the results will follow the linear equation of y=mx+b where y=I (current) and x=T (temperature) so I=mT. According to our testing, this is what happened. We found that as we raised the temperature of the water the current got higher too. However, as you can see in the graph above the results weren’t perfectly linear. But this could have been for many reasons which I will discuss in the next paragraph. Tying in with what was said before, with this testing there were faults and strengths in our testing. For most of our ideas our intentions were good, but the execution wasn’t as careful as it could have been. For example, we came up with an idea to start our water at the temperature zero degrees Celsius which would make it easier for us to monitor the temperature of the water, but it was hard to keep the temperature stable while also making it raise at an appropriate rate to allow us to view multiple states. This could have lead us to the faulty linear line that is shown in the graph above. Also, the voltmeter we were using was difficult to read. When ever we tested the current the number would jump all over of ranges over twelve hundredths amps. To solve this problem, we picked the number range that was the smallest and that rested on a single number for the longest period of time. Therefore, we may have picked inaccurate numbers for our current. In the future we may need to come up with an easier idea to change the temperature of the water as well as find an easier to read voltmeter. With the results that I have I can conclude that the amount of current in a given batter has a positive correlation to the temperature of the water, so that when the temperature rises, as does the amount of amps in a battery. For any other students working to create another battery with maximum power, but wish to control the temperature of the salt water I advise them to just keep it in a warm room with a thermometer in the water. I would just have them monitor it so that it stays at the same temperature through out the use of the battery.