• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10

How does concentration affect the rate of electrolysis of Copper Sulphate solution?

Extracts from this document...


How does concentration affect the rate of electrolysis of Copper Sulphate solution? Aim: In order to find out what factors affect the rate of electrolysis, we will change the concentration of the solution to find out which produces the highest current. Background information: Electrolysis is defined as: "The breakdown of a chemical substance by electricity." The following is the formula for what happens during electrolysis of Copper Sulphate Solution: 2CuSO4 (AQ) + 2H2O (L) 2Cu (S) + O2 (G) + 2H2SO4 (AQ) Reaction in the solution Copper + Oxygen + Sulphuric Acid Variables: The following is a list of variables that could effect the experiment: Table 1 Variable: Effect: Controlled: The concentration of the solution This is expected to effect the results, and will be the focus of the experiment. This will be the variable for the experiment The voltage flowing through the circuit With a higher voltage, the cathode would produce more copper Yes, the voltage will always be kept the same (9 volts) The temperature of the solution If the temperature is increased then the molecules will move faster and therefore more copper and oxygen will be produced. It will be kept at approximately 22 � C, (room temperature) but the temperature will be measure before and after the experiment The size of the beaker & The surface area of the electrodes that are in contact with the water. ...read more.


It must also be noted that Copper Sulphate Solution is poisonous, and the nitric acid is also very dangerous, therefore extra care will be taken around these two liquids. Diagram: Fig. 1 Results: The following tables are the results gathered from the experiment. Table 2 is the initial test, and tables 3 and 4 are the 'backup' tests that are taken in order to acquire an average in case of any errors in one particular recording. First experiment: Table 2 Concentration (ml) Current (MA) Temperature (�C) Color Before Experiment Mol/dm� water Initial End 0.5 0.5 0.61 24 25 Light Blue to Blue 0.6 0.4 0.83 23.5 24 Slightly Darker Blue 0.7 0.3 0.89 23 24.5 Still slightly darker, now medium blue 0.8 0.2 0.99 24 25 Darker, now almost dark blue 0.9 0.1 1.28 24.5 25.5 Darker still, verging on dark blue 1 0 1.24 23 24 Darkest yet, now dark blue. For the following experiments, (table 3 and 4) the color was not recorded, as it looked the same as previously stated in experiment one (table 2). Second experiment: Table 3 Concentration (ml) Current (MA) Temperature (�C) mol/dm� water Initial End 0.5 0.5 0.77 23 24 0.6 0.4 0.64 22.5 23.5 0.7 0.3 0.8 22.5 23.5 0.8 0.2 0.83 23 23.5 0.9 0.1 0.76 23 24 1 0 0.98 23 23.5 The yellow highlighted results shown in tables 3 (above) ...read more.


Also, for further investigation I could have weighed the electrodes directly after the experiment, to ensure that the only mass gained was through the extra copper. In addition the final weight of the electrodes could be measured at the end of each experiment, to attempt to determine the weight of copper deposited. Also, I could change the voltage on the power supply instead of keeping it at a constant 9 volts. This would give a more varied set of results that I could gather the average of. Finally, I to ensure better results I could try and use the exact same wires and the same electrodes along with keeping up with all the constants that are already in the experiment (such as the size of the beaker). Overall, the best-fit line (shown in Fig. 3) shows that this experiment was a success. The results indicate an upward trend between the concentration of the Copper Sulphate Solution and the Current recorded. Therefore showing that this experiment was a success. It is likely that even if this experiment was to be repeated the results would be similar and the best-fit line generated would be very similar, if not identical due to the fact that the anomaly shown is only just outside the margin of error. Through this experiment, it has been determined that an increase in the density of the concentration of Copper Sulphate Solution results in a higher rate of electrolysis, or an increase in the recorded current. Richard Coppock 1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Changing Materials - The Earth and its Atmosphere section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Changing Materials - The Earth and its Atmosphere essays

  1. Marked by a teacher

    An investigation to see how voltage affects The electrolysis in a copper Sulphate solution ...

    4 star(s)

    Errors could have been caused by the fact that not all the ions "stick" to the cathode, and so end up at the bottom of the solution. This happens most at higher levels of voltage there by causing an incorrect measurement of the weight for the cathode.

  2. Peer reviewed

    To find out how current affects the rate of electrolysis

    3 star(s)

    * A type of sludge formed outside the cathode Analysis: From this experiment I have found out that the current does affect the rate of electrolysis. As you can see from my graph and results the current 1 amp had the most amount of copper deposited on the electrode.

  1. Investigate whether changing voltage will affect the rate of Electrolysis.

    Proof of this is shown in my result table. Evaluation After carefully analysing my graph I think my results we obtained accurately. With my results I produced a straight line graph, which was one of my statements in my prediction. However there were some anonymous results between 8 volts and 9 volts.

  2. The Electrolysis Of Copper Sulphate Solution Using Copper Electrodes

    Also the concentration should remain constant. The amount of copper deposited on the cathode and lost from the anode depends on the number of electrons passing through the circuit, i.e.

  1. Investigate how the rate of electrolysis is affected when changing the current in the ...

    Other experiments that could be done in order to draw more conclusions on electrolysis include changing the concentration of the solution, changing the material used for the electrode, the size of the electrode and the temperature of the solution. Electrolysis - By Time Aim: To measure the rate of electrolysis

  2. Investigation to show how the amount of electric current affects the amount of copper ...

    His first law of electrolysis states that the mass of a given element liberated during electrolysis is directly proportional to the quantity of electrical current consumed during electrolysis. This supports my results entirely. The results of my experiment agree perfectly with my predictions.

  1. Investigate the factors that affect the mass of Copper deposited on the Copper Cathode ...

    The first reading: 0.2 amps Amount of electric charge = Current(A) x Time(S) 0.2 x 1200 = 240 C Number of moles of electrons transferred = 240 = 0.002487046632 96,500 At the cathode: Cu + 2e ==> Cu 1 mole of Cu ions requires 2 moles of electrons to form

  2. Investigating the factors that affect the amount of copper deposited during the electrolysis of ...

    I will set up the apparatus as shown opposite. The current values I will use will be 0.1, 0.2, 0.3, 0.4 and 0.5 amps. I will use these currents as I believe they will give a wide enough range of results giving me a good set of results to analyse fully.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work