• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Factors affecting mass of copper transferred in Electrolysis of aqueous copper sulphate

Extracts from this document...

Introduction

Factors affecting mass of copper transferred in Electrolysis of aqueous copper sulphate Using copper electrodes Different possible factors that affect the mass of copper transferred could be: * concentration of copper sulphate * time left in the solution * the temperature of the solution * the voltage * surface area of the electrode * distance between the electrodes * volume of copper sulphate * current Electrochemistry is a branch of chemistry that studies the reactions which take place at the interface of an electronic conductor (the electrode composed of a metal or a semiconductor, including graphite) and an ionic conductor (the electrolyte). If a chemical reaction is caused by an external voltage, or if a voltage is caused by a chemical reaction, as in a battery, it is an electrochemical reaction. In general, electrochemistry deals with situations where an oxidation and a reduction reaction is separated in space. Electrolysis is the decomposition of certain types of substance using electricity. The types of substance that can be split are ionic substances. Ionic substances form when a metal reacts with a non-metal. They contain charged particles called ions. For example, aluminium oxide forms when aluminium reacts with oxygen. It contains positively-charged aluminium ions and negatively-charged oxide ions. For electrolysis to work, the ions must be free to move. Ions are free to move when an ionic substance is dissolved in water or is molten. For example, if electricity is passed through copper chloride solution, the copper chloride is broken down to form copper metal and chlorine gas. Here's what happens during electrolysis Positively charged ions move to the negative electrode. Metal ions and hydrogen ions are positively-charged, so metals or hydrogen gas are produced at the negative electrode. Negatively-charged ions move to the positive electrode. Non-metal ions such as oxide ions and chloride ions are negatively-charged, so gases such as oxygen or chlorine are produced at the positive electrode. ...read more.

Middle

Five results would give us more evidence when plotting the line on the graph so we would do it more accurately. A curve only needs five points so my results are sufficient and I am also doing 0 minutes as a control to show that without the current there is only a slight movement of the molecules which doesn't affect the mass of the cathode. To ensure that these results are accurate I am going to keep the other variables constant as referred to in fair test and by using a stopwatch to time as it is more accurate than a clock, only wiping the cathode slightly before weighing it so it doesn't rub any atoms off. I will also use the equipment to help me because the variable resistor can keep the current constant giving more reliable results, the crocodile clips will hold the electrodes firmly in place and by putting them into a sheet of cardboard we can ensure that the electrodes stay the same distance apart. The scales give a more precise 2dp reading and by using propane to clean between each set of results it ensures that we start from fresh again. This method is a good way of carrying out the investigation because the only way the ionic bonds in the solution can be broken apart; i.e. with a current and by weighing the piece of copper before and after we can find exact gains. I used the preliminary experiment as a way to find out the right conditions needed and found that 0.5A gave very precise readings that went up steadily. I also found to make it easier we could place a piece of cardboard on top of the beaker with holes in to put the crocodile clips through and this would keep the electrodes the same distance apart. Also by using tape we could tape the wires down to the table so they did not get in the way. ...read more.

Conclusion

copper sulphate ionic solution is with a current and if the solution didn't separate then the ions wouldn't have been free to build up on the cathode. Also as we were trying to find the weight gained after each interval the best way to do that quickly and efficiently is to weigh it before and then after to find out the difference. However if I was to do this experiment again I would improve the method by making sure that the same ammeter was used each time we tested the different concentrations to make it more accurate, to sandpaper each cathode for the same amount of time to ensure that I have cleaned them all the same and as the electrodes were moving around a lot even with the cardboard I would take the crocodile clips to the edge of the beaker so they stayed in the same position. Other than this the method was good because it fitted what I needed to find out in the aim. I think that our method gave reliable results and were almost correct because it almost followed Faraday's law and my predicted results ( going up by 0.02g) as it was almost a straight line. The graph showed a strong, clear pattern so the conclusion was reliable. All the repeats were almost exact to each other so the averages must have been quite reliable. However these results could not always be counted on as correct because just because the pattern was correct it doesn't mean that every experiment scientists do are correct. They have to redo them several times before they get satisfactory results. If we had better equipment like the professional scientists do or we knew also the factors about the experiment e.g. fair test then our results would be more accurate. Reliable means that the results are dependable whereas accurate means correct results. There is a fine line between them so reliable results are not the same as accurate results. ?? ?? ?? ?? 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. The Electrolysis Of Copper Sulphate Solution Using Copper Electrodes

    electrode with lab coat, and washing it under the tap, some of the copper deposited was knocked off. Nevertheless, this washing process was vital because the need the eliminate the copper sulphate crystals that may grow on the electrodes from time to time.

  2. Importance of electrolysis in our daily lives

    efficiency, which loses a lot of energy as heat to the surrounding environment. The hydrogen fuel cell has less movable parts and does not lose as much energy during its reaction. Another advantage of hydrogen as a future energy carrier is that it is easy to store and distribute and it can be done in many ways (Kroposki 4).

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

    This is unlikely; instead, it is more probable that the current flowing through the circuit and the electrodes produced resistance that caused the slight rise in temperature. From the graph it can be seen that whilst there is no specific formula or ratio for the current generated in relation to the concentration (e.g.

  2. What Effects the Reaction in the Electrolysis of Copper Sulphate.

    I can do this because I will know how many coulombs I want to pass through the circuit. Below is an example of how this can be accomplished: charge = current X time Therefore: time = charge / current

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

    I have drawn this graph in order to prove the prediction that I made in which I stated that copper ions from the anode will be released into the copper sulphate solution and so the anode would get lighter.

  2. Investigating how the amount of copper affects the mass of the cathode

    One Faraday of electricity contains 1 mole of electrons An example for Faraday's second law of electrolysis is during two different electrolysis experiment 1.08g of silver was deposited and 0.32g of copper was deposited.

  1. Thermal Decomposition Of Metal Carbonates

    So instead of using 125gms I will use 1.25gms. I have constructed a table below which clearly shows the way in which I have calculated the mass for each carbonate that I am to use: Carbonate Formula Elements within Atomic mass Number Working Total Divide by 100 Zinc ZnCO3 Zinc 65 65 + 12 + (16�3)

  2. An investigation to find out what factors affect the rate of electrolysis of a ...

    In order for any reaction to happen the particles must first collide. This is true whether both particles are in solution, or whether one is in solution and the other a solid. If the concentration is higher, the chances of collision are greater as there are more of the particles

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