Research Question/Aim: How does the current of a cell affect the percentage change in mass of the copper strip on the negative electrode? The aim of this experiment is to record how the change in current of the cell changes the percentage change in mass of the copper strip. Basically, the percentage change in mass will be taken from the negative electrode because the negative electrode is where the reduction occurs and the mass will increase.
The current will be increased by increasing the voltage of the cell and the certain current will be recorded for 6V, 8V, 10V, 12V, and 14V. There will be three trials for each of the five different currents. 1) First, set up the area by having the power supply plugged in, the ammeter set up with the wires in series and the voltmeter set up in parallel. Also have the stop watch ready and the voltage set to 6V. 2) Fill up a 250ml beaker with 200ml of 1 molar Copper (II) Sulfate
3) Measure the initial mass of the copper strip you wish to use and place this copper strip on this copper strip on the negative electrode using a crocodile clip 4) Place another copper strip on the positive electrode of relatively the same size 5) Turn on the power supply (6V) and then place the two copper strips in the Copper (II) Sulfate solution. Simultaneously start the stop watch. Make sure you record the current from the ammeter. This would be the current for 6V.
Hold the copper strips in the solution for a total of 300 seconds (5 minutes) 7) Pull out the copper strips and place the copper strip, from the negative electrode, on a tissue. After this strip has dried measure the mass and record the final mass of the first trial. 8) Repeat steps 3 – 7 two more times for two more trials. 9) Repeat steps 3 – 8 for 8V, 10V, 12V, and 14V. Overall, you should end up with 3 initial masses and 3 final masses for each of the five different voltages/currants.
These results will later be calculated to find the average percentage change in mass. The table above shows the raw data collected from this experiment. To process the data there are multiple steps. An example of how to process the data into Average Percentage Change in Mass is shown below: First, the average of the final mass must be calculated: (0. 57 + 0. 60 + 0. 47) / 3 = 0. 55 g Then, after the average final mass is calculated the following formula is used: = 7. 8% Therefore, the average percentage change when the currant is 0. 28 amps is 7. 8%.