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Tuesday, April 2, 2019

Effect of Voltage on the Rate of Electroplating a Metal

Effect of potential on the Rate of Electroplating a MetalAkinlabi Boluwarinde OluwatosinBACKGROUNDElectroplating is the process of plating one metallic element onto some other by hydrolysis, most commonly for decorative purposes or to prevent corrosion of a metal. There ar too specific types of electroplating such as slovenly person plating, silver plating, and chromium plating. Electroplating allows manufacturers to accustom inexpensive metals such as steel or zinc for the majority of the p retinal roduct and then fall in different metals on the outside to account for appearance, protection, and other properties sought by and by for the product. The bob up can be a metal or even plastic.1 inquiry QUESTIONHow does varying the electric potential of the duty tour affect the rate of electroplating a metal with copper?HYPOTHESISThe voltage of the cell also cognize as the E.M.F (electromotive force) is known to be the force that drives the current thhrough the circuit. It is pass judgment that by increasing the Voltage the circuit get out lead to an increase in the rate of electroplating the metal as more than current will menstruate easily passim the circuit.VARIABLESIndependent VariableThe voltage of the circuit aqui demarcation line VariableThe can of dainty copper electroplated onto the metalControlled VariableThe beat of time allowed for responseThe concentration of the electrolyte solventThe metal rod applyCONTROL OF VARIABLESThe amount of time allowed for reaction to occur will be measured with the use of a stopwatch. The voltage of the circuit will be increased by a fix aed amount of 1.5V to take note the investigate and easily measure a changein rate. The same metal rod will be use throughout the prove for all trials and of the different voltage. The throne of the metal rod to be apply is 7gAPPARATUSCellsLow unsusceptibility wireCopper solidElectrolyte (copper sulphate solution)Electric BalancestopwatchMetal rodVoltmeterBeakerM ETHODI Setup the circuit as shown in the diagram below.I measured the initial circle of the metal and recorded it.Starting with one cell of 1.5V.I closed the circuit and allowed the reaction to occur for 10 proceedings. I removed the electroplated metal and measured its muss and recorded it in the table.I Repeated the experiment increasing the trope of cell apiece time and recorded the mass of the of the electroplated metal each time.SAFTEY PRECAUTIONSThere is the risk of electrocution if care is non taken. To avoid this the use of surface protected wires is necessary and great care must be taken when carrying out the experiment.DATA COLLECTIONRaw informationVoltage /vMass of metal rod after electrolysis /g 0.1g racetrack 1Trail 2Trail 31.57.87.97.93.08.98.78.84.510.09.99.96.011.111.210.9Qualitative ObservationsThe pure copper solid utilize became faded after it was used in the electrolysis reaction.There was still some resi repayable of copper left on the metal rod after rinsing it.The voltage recorded by the voltmeter was not constant however varried in range that was close to the desired valueThe mass of the metal rod used is 7gProcessed DataVoltage /vMean Average mass of metal rod after electrolysis /g 0.1gMass of copper added to rod /g 0.1g1.57.90.93.08.81.84.59.92.96.011.14.1The info has been processed. The mean of the three trials for each voltage has been calculated and represented on the table in a higher(prenominal) place as Mean Average mass of metal. withal the mass of copper that was electroplated onto the metal rod was calculated using the equatingGraph 1Graph 2CONCLUSIONAs expected when there was an increase in the voltage menstruum in the circuit the mass of copper that was electroplated onto the metal rod increased too. This is because as the voltage increases a larger number of electrons flow from the cell or onslaught into the anode which causes the formation of copper ions to occur faster and so more ions are attracted to the metal rod (cathode) in the given time.The relationship between mass of copper electroplated and voltage can be seen on both chartical record 1 and chartical record 2 above. In graph 1 there is an increase in mass as voltage increases but the graph obtained is a slight curve rather than a straight line which indicates random fractures, this could likely be ascribable to the voltage fluctuating in circuit.Graph 2 shows a line of best fit for the graph and it is a straight line graph as expected, the error bar are plotted as well. The line passes through all the error bar ranges but does not touch any of the points on the graph and it does not pass through the origin (0,0), this may be due to systematic errors such as errors in the electric balance when meter the mass of the metal rod before and after electroplating. The linear correlation is 0.998, which suggest really strong correlation between the two variables. ratingThe graph of values obtained was not exactly the sa me as what was expeted. A straight line graph starting from the origin was the expected graph but the graph ontained after a lin of bestt fit was plotted started from the y-intercept -0.25. This was due to errors in the experiment. Random errors such as the fluctuation of the voltage flowing through the circuit as a result of the chemicl reactions going on in the cell led to some of these errors. The voltmeter showed values that ranged from below to above the value of the voltage required indicating that this variable was not kept constant. The deviations were very little and not too far from the required voltage but were still enough to cause errors. It is also possible that because the same solution was used for all trials not all the copper ions had been electroplated onto the metal rod, this could learn altered the concentration of the electrolyte (copper sulphate) leading to more errors as the concentration of the electrolyte also has an effect on the rate of electroplating.Sy stematic errors were also present throughout the experiment, errors in measuring the mass of the of the metal rod before and after electroplating and also in measuring the mass of the anhydrous copper convert solution. This may have been due to poor caliberation before the experiment was carried out. The copper used may also have not been pure as it is possible that there were impurities in the copper solid used. Finally not all of the copper was rinsed off the metal rod before it was used for the next trial which could have altered the total mass when the mass of the metal after electro plating was measured. Errors in measuring the volume of body of water to be added to the beaker could also have been present. Systematic errors in the stopwatch used such as the delay in starting when the timer was started. The experiment also depended on human reaction time which is known to little accurate than machines, this will have led to more errors.It is impossible to keep the voltage of the cells constant but the range of values can be reduced by using new cells. The eleectric balance cshould be well caliberated before carring out the experiment and a balance with a higher degree of accuracy and sensitivity (measures to more decimal places) could be used. in the beginning each trial a new electrolyte solution could be used to avoid any changes in concentration during the experiment. The experiment could have been machine-controlled using a switch that opened after ten minutes from when it was closed to eliminate the error as a result of dependance on human response time. The experiment could also have been repeat more times to reduce errors and increase accuracy. Also a laager rane of voltages could have been tested to gain more data for better more accurate analysis.1http//chemwiki.ucdavis.edu/Analytical_Chemistry/Electrochemistry/Electrolytic_Cells/Electroplating

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