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

An investigation into whether the voltage affects the amount of gas produced during the electrolysis of sodium chloride solution.

Extracts from this document...

Introduction

An investigation into whether the voltage affects the amount of gas produced during the electrolysis of sodium chloride solution. Prediction: I think that hydrogen gas will be produced due to the half equation 2H +2e -->H this will be produced at the cathode because opposites attract and the hydrogen ions are positive. At the anode I think that chlorine will be produced due to the half equation 2CL -2e -->CL the chlorine ions are negative so they are attracted to the positive electrode. I also think that as the voltage is increased the amount of hydrogen gas produced will increase this is because of a series of scientific equations: if the voltage is increased the current then is increased, this is because of ohms law, V=IxR, where the voltage is proportional to the current, if the current is increased the charge then increases because Q=IxT. The number of moles of electrons=charge -:- 96500, this is Faradays constant from his 2nd law. The relationship between the amount of substance deposited at an electrode and the number of electrons that are passed around a circuit (current) can be used to calculate the expected volume of substance produced at the electrode. To find the amount of hydrogen gas produced at the electrode we would multiply the number of moles of hydrogen gas by 24, this is the area that one mole of any gas will occupy. ...read more.

Middle

take averages Fair test points * Temperature- has to stay the same so it doesn't speed up the process of electrolysis * Time- the amount of gas produced could be increased or decreased depending on whether the experiment is done for a different period of time. * Molarity- if the solution of brine is stronger or weaker the rate of electrolysis could become faster or slower * Amount of solution- if there is more solution then there is more room for the electrons to flow across the solution as ions and more gas can be produced * The size of the electrodes-this has to stay the same because if there was a really short electrode this would produce less gas compared to a longer one. * Surface area of electrodes-It has to have the same surface area to stop more gas being able to be produced * The distance between the electrodes also has to stay the same as the ions would have to travel further and it would take a longer time than if they were really close together. * Between each experiment the electrodes need to be sanded down, there then won't be any substances on the electrode to make it harder for the ions to get through. ...read more.

Conclusion

I think that my results would support my conclusion to a high extent, the higher the voltage the steeper the graph got, I think this pattern would hold true at the extremes of the range. Evaluation This experiment was overall very accurate and the evidence obtained was very reliable. I repeated my results and took 6 measurements. When I did repeat my results I got similar ones that were very close to the line of best fit. I had one anomalous result which may have been because I used a different bottle of brine this could have been a different concentration or the change from a plastic measuring cylinder to a glass one could have upset the experiment. To improve this experiment I would use a 25 volt lab pack with bigger measuring cylinders this would allow me to see if the pattern was still the same at the higher extremes of the range. Instead of using the measuring cylinder I could use a gas syringe this would be a lot more accurate. Another factor could have been the electrodes, which, even after a good clean were still quite dirty and obviously still had irremovable substances from previous experiments still attached to them. If this experiment were to be repeated for a second time, in need of greater accuracy, I would get a new electrolysis cell, with clean electrodes which have never been used before. ...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. Peer reviewed

    To find out how current affects the rate of electrolysis

    3 star(s)

    These will migrate to the positive anode. The hydroxide would lose it's oxygen. The evidence to this is that during the pre-test you could see fizzing and bubbles coming off the anode. In this case the hydroxide ion is discharged by loosing its electron to form water and oxygen, 4OH- - 4e- = 2O + 2H2O.

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

    By changing the volts to 2, there was enough push to bring a reaction. Thanks to the preliminary experiment we knew the amount of each variable to conduct the actual experiment. Method; What we did Apparatus/Equipment Power Pack Graphite Rod Copper Sulphate (CuSO)

  1. Investigate whether voltage affects the rate of electrolysis?

    crocodile clips, a power pack, a beaker, a timer, an ammeter and a hair dryer. Method: * First you get the beaker with 200ml of copper sulphate. * weigh the two pieces of copper (these are your electrodes) before starting so that you can compare it to the weights of them when the experiment has been completed after each voltage.

  2. Investigating how the voltage produced by a simple cell is related to the reactivity ...

    This is two metals combined which lowers the voltage produced. Apart from these two errors, which can be explained, my results are fairly accurate which shows that reactivity and voltage produced are linked in some way. Now I believe that it is not the reactivity that creates the voltage but the difference in reactivity between the two metals.

  1. The Electrolysis Of Copper (ii) Sulphate Solution Using Copper Electrodes

    This means that the loss in Copper deposits would be more evident as the increased rate of reaction wouldn't compensate for this loss in mass. Also very small amounts of Copper were deposited and so even a small loss would be large as a percentage of the entire mass.

  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 effect of the amount of sodium chloride, i.e. concentration gradient, in the ...

    Also, from my preliminary work, I found that the current and voltage for solution with10g NaCl is: Current(A) -10.00 -8.00 -6.00 -4.00 -2.00 Voltage(V) -2.73 -1.88 -1.03 -0.30 0.00 And the current and voltage for solution with 30g NaCl is: Current(A)

  2. Quantitative electrolysis concerns the amount of product obtained in an electrolysis, and the various ...

    This quantity of charge can be applied to ionic half equations, to work out the mass of product obtained when a certain amount of charge is passed during an electrolysis. Consider the following; Cu2+(aq) + 2e- ? Cu(s) [Cu = 63.5] ==> This equation shows that ( 2x 96,500 = 193,000 )

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