Science investigation report Essay Example for Free

Science investigation report Essay The moment the paper clip is dipped in, time the electroplating process for 30 seconds. 10. After 30 seconds, take out the paper clip, switch off the power supply and weigh the final mass of the paper clip. 11. Repeat step five to eleven a second time to obtain a second set of results. Use a new paper clip each time when repeating the steps. 12. Repeat step five to twelve, increasing the voltage of the current by 2V each time. 13. Tabulate the results. Results The table shows the changes of masses in the initial and final mass of the paper clips when undergoing electroplating at different voltages. Voltage of Electric Current (V) Trial 1 Trial 2 Average Mass Change (g) Initial Mass (g) Final Mass (g) Mass Change (g) Initial Mass (g) Final Mass (g) Mass Change (g) Graph Analysis of Results and Graph. After conducting the experiment, it is found that when the voltage of the electricity from the power supply was 2V (the least voltage among the others), the mass change in the paper clip before and after the electroplating process was the least, which meant that the rate of electrolysis was the slowest here, hence the mass of the copper metal plated onto the paper clip was the lightest. As the voltage of the electric current increased by 2V gradually each time, the mass change in the paper clip before and after electroplating increased as well, this meant that the mass of the copper metal plated onto the paper clip also increased. This meant that when the voltage of the electric current was at its largest (10V), the mass change of the paper clip before and after the electroplating process was the largest, and hence the mass of the copper metal plated onto the paper clip was the heaviest. As the voltage increased by 2V each time, the mass of the copper metal deposited onto the paper clip mostly increased at a constant rate of 0. 004, with the result at 8V being a little off, but still valid. The graph shows how the voltages of the electric current affect the mass change of the paper clip before and after the electroplating process. It is a linear graph, where the gradient of the graph increases constantly at the same rate. There is a rather positive association between the voltage and the mass change in paper clip, and the strength of the association is strong, so it is safe to say that both variables are directly proportionate to each other. Throughout the entire experiment, the gradient increased at a proportionate rate, which indicates and proves that the formula Q = It and V = IR is true and is directly proportionate. Hence, at the lowest voltage, the mass of copper metal deposited on the paper clip was the least and at the highest voltage, the mass of the copper metal deposited on the paper clip was the most. Conclusion The results from the experiment showed that as the voltage of the electric current increased, the mass of the copper metal deposited on the paper clip also increased. Therefore, I can say that my hypothesis is supported and correct. This is because when the voltage of the electric current increased gradually, the current in the circuit increased as well. As the current increased, the charge of the electric current increased as well, as said so in the formulas. This would mean that the flow of electrons is faster; hence the rate of electroplating would also be faster. This would mean that the mass of copper metal deposited on the paper clip within 30 seconds would also increase. Therefore, as the voltage of the electric current increases, the mass of the copper metal deposited on the paper clip also increased. Reliability I can say that my experiment is rather reliable because I repeated everything 2 times to get the average results so that the results would be more accurate. There were no problems and the results when repeated, were rather similar to each other except for one or two sets where the difference varied by 0. 014g and 0. 010g. This probably happened due to the uncontrolled variable the surface area of the paper clip submerged in the electrolyte. The apparatus used were all reliable and in good condition, with none being broken. The method was as precise as possible, taking note of everything and the details. For example, I tried to make sure the surface area of the copper metal piece submerged in the electrolyte was constant each trial at 0. 7cm2 so that it would be fair. I also measured each of the 10 paper clips individually because no one paper clip has the same weight so it would be unfair to assume that all paper clips has the same mass. The method described and explained every step, and provided the results needed. The results analysis were described and explained with as many details as possible, and there were no miscalculations and major errors during the experiment. Validity The experiment was valid, as the apparatus used measured everything needed, for example, I used a 20cm ruler to measure the surface area of the copper metal piece to be submerged into the electrolyte. The 25cm3 measuring cylinder could have been replaced by a 50cm3 measuring cylinder to measure 100cm3 of CuSO4 solution, but then due to limited number of apparatus, a 25cm3 measuring cylinder was used. Nonetheless, it still fulfilled the requirements of measuring 100cm3 of CuSO4. The balance used to measure the mass of the paper clip was electronic, so there were no zero errors either. The method was valid as the dependent and independent variables were measured and results were obtained. The hypothesis was valid as the outcome of the experiment supported it. Limitations and Improvements If I could do the experiment again, The results could be repeated a couple of times more for more accurate results, and a few more sets of results could be taken, to broaden the set of results. This could give a clearer graph, as the graph could show more prominently that it is linear if there were more sets of results. When the paper clips were submerged into the electrolyte each time, the surface area of the paper clip submerged was not accurately constant throughout, as I had only estimated the approximate surface area for each paper clip. I could have bent the paper clip into a long thin metal wire and measured the length that would be submerged in the solution, as this would help further ensure that the surface area of the paper clip that was to be electroplated to be more constant. Instead of using the same copper sulphate electrolyte for the entire experiment, I could have changed the solution after every trial, as after some of the trials I could see a thin film of copper left on the surface of the solution. To ensure that this would not affect the experiment results, I could have used a new copper sulphate solution for each trial.