Electrolysis Investigation
Planning I did some preliminary work to see which current values, and for how long to time. The results of this are in the tables below: Electrode-1A Mass before (g) Mass after (g) Mass change (g) Anode 1.38 1.30 -0.08 Cathode 1.35 1.65 +0.30This was done for 10 minutes. The mass lost at the anode should equal the mass gained at the cathode, which this doesn't, it has a percentage inaccuracy of 0.22¸ .30x100= 73% which is very inaccurate, This may be due to the current being too high, so the copper does not all transfer properly, but lies on the bottom of the beaker, therefore a lower current must be used, as in the table below: Electrode-0.1A Mass before (g) Mass after (g) Mass change (g) Anode 1.42 1.35 -0.07 Cathode 1.16 1.21 +0.05This was also one for ten minutes, and shows much more accurate results, as the percentage inaccuracy is only 0.02¸ 0.07x100=29%, which is still inaccurate, but is a lot better . This could be due to the current value being to low, so I will take a range of 5 results from 0.1Amp to 1Amp at 0.2Amp intervals. Each electrolysis will last 10 minutes, and each will be repeated twice so that a more accurate average can be taken. Variables * Temperature of the electrolyte * The concentration of the electrolyte * The separation of he electrodes * The
Electrolysis Investigation
AIMS It is known that by passing a constant electric current through an aqueous copper sulphate solution that the passage of ions through this solution results in copper atoms being dissolved into the solution from the anode while positive copper ions (cations) being discharged at the cathode. Normally anions are discharged at the anode. The experiment carried out aimed to monitor the quantity of Copper (Cu) metal deposited during the electrolysis of Copper Sulphate solution (CuSo4) using Copper electrodes, when certain variables were changed. It was considered that the following factors could affect the deposition of Copper metal on the cathode. . Time 2. Current 3. Temperature 4. Molarity/Concentration of Solution 5. Quantity of Solution 6. Size of Electrodes 7. Distance between the electrodes 8. The surface of the electrodes The time was chosen because it is an easy quantity to measure and record, whilst at the same time maintaining the other variables at a constant level. The other factors could be observed in later experiments, should time allow. PREDICTIONS It is possible to predict that the relationship will be directly proportional between the time the current flows and the mass of Copper deposited on the Cathode (negative electrode). I can therefore predict that if I double the time of the experiment, I will therefore be
Electrolysis Investigation
PHYSICS COURSEWORK. Prediction. Electrolysis is the method of using electricity to separate two solutions. This works by passing electricity through the anode, (the positive electrode,) through the solution and then back up the cathode, the negative electrode. In this investigation we will be using Sodium Chloride (commonly know as salt) to react. If the ions are positively charged then they will be attracted to the cathode, the negative electrode, and if they are negatively charged then they will be attracted to the positive electrode, the anode. When we use the Sodium Chloride then the sodium ions will be attracted to the negative electrode and the chlorine ions will be attracted to the positive electrode. If we increase the concentration then the reaction will happen faster because there are more electrons and so the chance of a reaction happening is increased. The current is the flow of Ions in the electrolyte cell, so more Ions means more current. Variables. { [image001.gif] Material of the electrode. { Concentration. { Voltage. { Temperature. Independent { Surface area of the electrodes. Variables. { Distance between the electrodes. { Current. - Dependent variable. Apparatus. { Goggles. { Electrolysis Cell. { 6-Volt Power Pack. { Distilled Water. { Sodium Chloride. { Measuring Cylinder. {
Electrolysis of Sodium Chloride - NaCl.
Electrolysis of Sodium Chloride - NaCl Plan Aim I aim to find out how the concentration of Sodium Chloride (NaCl) affects the current. Hypothesis Electrolysis is the decomposition of a substance or compound with the use of electricity. Electricity is the free-flow of electrons (or charged particles). An electrical current is only able to pass through a substance if the electrons (or charged particles) are able to move. Graphite's electrons are free to move, hence it is a conductor of electricity. Ions enable charges to move freely in solutions, and therefore also are conductors. There are two graphite electrodes; the negative electrode - the cathode, and the positive electrode - the anode. In this experiment the ions present are; NaCl = Na+, Cl¯ H2O = OH¯ and H+. Therefore; At the cathode; Na+, H+ The most reactive out of these remains in the solution ; 2 H+ +2e¯= H2 (g) Here, we experience a gain of electrons, called a reduction At the anode; Cl¯, OH¯ If a halogen is present, halogen gas given off - Cl2 Here, we experience a loss of electrons, called an oxidation Left in the solution; Na+, OH¯ Prediction I predict that as the concentration of Sodium Chloride (NaCl) is increased, the current will increase also. I think this because the current and concentration are proportional; electricity is the free-flow of electrons (or charged
The Reactivity Series.
The Reactivity Series. Aim: To find the order of reactivity using 5 metals; Magnesium, Copper, Zinc, Iron and Calcium. I will find the order by adding each metal with Copper (ii) Sulphate, (Cu SO4), and finding there exothermic temperatures through out the experiment. Prediction: I think the order of reactivity for these five metals will be: Calcium, Magnesium, Zinc, Iron and Copper. This is because of where each metal is placed in the Periodic Table. Group 1 and 2 are more reactive than the transition metals, and the further you go down a group, the more reactive the metal gets. That is why Calcium is one period below Magnesium. Iron, Zinc and Copper are transition metals, meaning they come last. To find out the reactivity of the transition metals, you see how reactive each one is when it is added to an acid and water solution. No experiment is needed to be carried out with Copper, as Copper (ii) can not displace it's self in the solution - Copper (ii) Sulphate. The results will probably stay the same as the room temperature or even the temperature of the Copper (ii) Sulphate. Though, to make these experiments a fair test, and to be certain that my hypothesis is correct, I shall do the Copper experiment. I think the graphs will all start at room temperature and as soon as the Cu So4 is added the temperature will rise. Of course Calcium will be the
Whether the voltage affects the amount of gas produced during the electrolysis of sodium chloride solution.
Electrolysis Coursework Aim An investigation into whether the voltage affects the amount of gas produced during the electrolysis of sodium chloride solution. Prediction When electrolysis of sodium chloride solution takes place there are four ions produced. These are Na+, H+, Cl-, OH-. The sodium and hydrogen are attracted to the cathode but it is the hydrogen given off because it is the less reactive of the two. The half equation for this is H+ +2e›H2. The chloride ion and hydroxide ion will be attracted to the anode because they are both negative but it is the chloride ion that will be given off because it is always the halogen that is given off. The half equation for this is 2Cl- -2e›Cl2. I also predict that increasing the voltage which will increase the current, which will increase the number of electrons flowing which will increase the volume of gas given off. Preliminary When conducting this part of the experiment I started off by trying the experiment on the lowest reading on the power pack which was 0.2v. This was to low as it would take too long to get a good reading so I put it up to 4.0v which was adequate as it only took 30s to get a good reading, so I used 4.0v, 4.2v, 4.4v, 4.6v, 4.8v 5.0v. Diagram Method . Set up equipment as above. 2. Fill a measuring cylinder with water, and invert over the cathode. 3. Set the power pack at the voltage required.
