Chemistry IA: Electrolysis of Metal Sulphate solutions Essay

IntroductionElectrolysis is the chemic decomposition of a compound by applying an electric current through a solution containing ions. Electrolytes atomic number 18 required to conduct electricity. They must be dissolved in water or in break up state for the electrolytes to conduct because therefore, the ions are free to move allowing the solution to be electrolyzed.1 In electrolysis, reduction happens at the cathode whilst oxidation happens at the anode. Reduction is the loss of electrons and oxidation is the gain of electrons.Research QuestionIn this experiment, I depart be electrolyzing plate note sulphate (NiSO4) solution. To further explain the aim of this experiment, I have explicate a research question How does changing the current affect the dope of nickel deposited at the cathode in the electrolysis of nickel sulphate?HypothesisI predict that as the electrical charge increases, the mass of nickel deposited at the cathode after electrolysis leave behind in addition increase. Faradays law of electrolysis, which investigates the quantitative relationship on electrochemical, crowd out support this. Faradays law states, The aggregate of the substance produced by current at an electrode is directly comparative to the quantity of electricity used.2During this electrolysis experiment, the aqueous solution of nickel note Sulphate testament transfer Nickel from the anode to the cathode. Therefore indicating that the nickel sulphate solution is ionised by the electric current and dissociated into nickel ions and sulphate ions. This can be represented in a chemical equation NiSO4 Ni2+ + SO42-At the cathode, positively supercharged nickel ions are formed there and Ni2+ ions are reduced to Ni by gaining two electrons Ni2+ + 2e NiAt the anode, Ni is oxidised into Ni2+ by dissolving and going into the nickel sulphate solution and final examly depositing nickel at the cathode Ni Ni2+ + 2eWhen the electrolysis circuit has electricity aerodynamic, the nickel ions pull up stakes float towards the electrode. Therefore, when the current is increased, the nickel ions flow faster and reaching the cathode faster. So there will be more nickel deposited as the rate of electrolysis is increased.Independent and Dependent VariablesVariable heedfulMethod of measuring uncertainIndependent variableMagnitude of current flowing into the electrolytes (A)The 5 values I will use for current flowing into the electrolytes will be0.5 amps1.0 amps1.5 amps2.0amps2.5 ampsTo vary the values of current, a variable resistivity will need to be used in the ciruit to control the flow of current. The amps values can be determined utilize an ammeter, which is also extended to the electrolysis circuit.Dependent variable mess of Nickel (g)The mass of nickel deposited at the cathode after electrolysis will be measured for results. This will be determined by weighing the nickel electrodes before the experiment and after electrolysis. For this, a electronic ba lance will be used to weigh them.Controlled VariablesVariable measuredMethod of measuring variableControlled variablesTemperature (C)The entire experiment will be done in means temperature of around 24C to ensure that the temperature for each trial will be the same. The temperature will be measured development a thermometer.Concentration of solution (moldm-3)The concentration of nickel sulphate needs to be unplowed constant at 1 moldm-3. This is because the same concentration will allow the number of ions in the solution to be the same, thus the number of collisions during the electrolysis will be unploughed the same.Volume of solution (cm3)The saturation of nickel sulphate for each trial will be kept at 100cm3. Measuring cylinders will be used for blameless measurement.Time (min)The timing for the experiment needs to be controlled very conservatively to ensure the amount of current passing the electrolytic cell will have the same amount of time. For each trial, it will run fo r 2 minutes. This will be determined using a stopwatch.potential (V)To keep the voltage of this experiment constant set at 5V, we only need to switch the mogul pack to 5V and keep it there.Distance between electrodes (mm)The distance between the nickel electrodes needs to be kept constant so it doesnt affect the amount of current passing. The distance will be kept at 40mm and this will be measured using a prescript.Surface of electrodesBefore using the electrodes in the experiment, sand paper will be used to require the oxide layer on the sheet of nickel. This will ensure the surface of all electrodes to be the same and will have the same surface for ions to attach to.Size of electrodesThe electrodes need to be kept the same size to ensure there will be an equal surface area for nickel to deposit on. The nickel sheet electrodes will be 10mm by 50mm long. This is measured using a ruler.EquipmentEquipment such as measuring cylinders, power packs, wires will need to be the same. This is because different equipment would have different uncertainties, which may affect the final readings of the experiment.EquipmentThermometerNiSO4 solutionNickel electrodes100ml beakerResistor author packAmmeterDiagramSafety considerationsLong hair needs to be tied back prehend footwear worn for laboratory experimentsSafety goggles should be warn to prevent harmful chemicals from harming your eyeballDont touch the electric terminals when the electricity is on to prevent shocksReliable resultsTo ensure accurate and reliable results, I will be undergoing 3 trials for each experiment. This is so I will then be able to calculate an average, thus my data will be more reliable. I will also maintain all the controlled variables and only varying the input of current.MethodSet up the machine and circuit as shown in the diagramFill a beaker with 100cm3 of nickel sulphateWeigh the cathode using the electronic balance and record the initial mass of itFile the Nickel electrodes using sandpape r to remove any impuritiesPlace each electrode pair into the beaker with nickel sulphateAttach the electrodes to opposite sites of the beaker (measure with a ruler the distance between, it should be around 4cm) by bending the electrodes itAdjust the current to 0.5 amps using the variable resistorConnect the electrolytes into the circuit by clipping on the wires and turn the power pack on utilise the stopwatch, time for 2 minutes whilst looking at the ammeter to ensure the current remains the same later on 2 minutes, turn the power pack off and take the cathode out.Wash the cathode carefully with distilled water and ironical it with a paper towelWeigh the cathode again using the electronic balance and record the massRepeat the steps 1 to 12 again for 1 amps, 1.5 amps, 2 amps and 2.5 ampsInitial Mass of Cathode (0.001g) lowest Mass of Cathode (0.001g)Change in mass(0.001g)Average mass gained (0.002 g)Data tableThe table preceding(prenominal) is a draft up of the raw data results tab le I will be using for my final readings from the experiment. It includes columns with headings, 3 trials, units and uncertainties and the average mass gained from the whole experiment. From these results, I can also draw a graph to easier represent the data and can also spot patterns or anomalous data that pass by in the results.The actual theoretical mass of nickel deposited at the cathode can also be calculated with a few equationsCharge (C)= Current (A) x Time (s)Moles of electrons= Charge (C)/ 96500Moles of Nickel= moles of electrons/2Mass= moles x RAMThe total percentage of random uncertainty can be calculated for my final answer in order to determine whether my experiment was fully successful and that the results are accurate.WiresCrocodile clipsStopwatch smoothenRulerElectronic balance________________1 Neuss, Geoffrey. IB Study Guide Chemistry Study Guide. s.l. Oxford UP, 2007. Print.2 Faradays laws of electrolysis. Encyclopdia Britannica. Encyclopdia Britannica Online.Enc yclopdia Britannica Inc., 2012. Web. 04 Oct. 2012.