In this experiment, I will be testing the corrosion rate of copper wire after leaving them in different liquids with different pH levels. By doing so I will be able to determine which pH level corrodes copper the fastest. I will conduct this experiment by pouring 250mL of different liquids with different pH levels in cups, followed by an iron strip placed into the cup. A stopwatch will be timing how long it takes the iron strip to fully corrode. The cups will be placed in the same environment right next to each other in order for the cups to be in the same temperature. All of the cups will be the same type of cup to make sure the cups won’t have a role determining the results.
There will be three trials for each type of liquid. This will ensure the most accurate results. The pH level will be tested with a strip of litmus paper to determine the official pH level of the liquid. The stopwatch will start as soon as all of the copper wire are placed into the cups. I will be watching the cups, taking note of any qualitative data I see. When I see that the iron strip in one of the cups is fully covered in rust, I will record the time that was on my stopwatch. To analyze the data I will first find the average pH level for each of the liquids. Then I will average the total time it took for the copper wire to corrode. This data will be in hours. To see if there was any correlation between the independent variable and dependent variable, I will create a graph with the time it took the copper wire to corrode as the y-axis and the pH level as the x-axis.
Hypothesis: If the pH level is more acidic, than the iron strip will corrode at a faster rate. Independent Variable: pH level of liquids
Dependent Variable: rate of corrosion of iron strip
Control: pH of 7 (Tap water)
• Same amount of liquid in each cup (50mL)
• Same sized copper wire (5"x3/4"x3/64")