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

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

Extracts from this document...

Introduction

An investigation to see how voltage affects The electrolysis in a copper Sulphate solution using copper electrodes. Aim To find out how the voltage affected the electrolysis in a copper sulphate solution by weighing the amount of copper that was on the anode and the cathode and then comparing the difference from before the electrolysis. Theory Electrolysis is the process of decomposing the compounds by electrical energy and an element is produced at each electrode. In this case I have chosen copper sulphate solution to electrolyse. In the experiment when the solution is being electrolysed it starts to decompose and at cathode there is copper formed and oxygen at the anode. This is caused by electricity from the power supply, which has caused a chemical change. The reaction, which occurs at the cathode, is: Cu2+ (aq) +2e- � Cu (s) The reaction, which occurs at the anode, is: Cu (s) � Cu2+ (aq) + 2e- Variables The possible independent variables that could have been tested in this test are the following; the amount of copper sulphate in the beaker, the current, the voltage, the size of anode and cathode, the duration of time given for it to electrolyse and the distance between the anode and the cathode whilst inside the electrolyte In this test we have decided to set the voltage as our independent variable. ...read more.

Middle

Also each test had exactly 3 and half minutes each. Safety As this experiment is mainly based around electricity the main hazard is from electrocution especially as there is a liquid near by therefore we need to particularly work slow and carefully and any electrical equipment. Diagram of the experiment Method The equipment listed will be set up as followed in the diagram. The anode and cathode will be weighed accurately then recorded up on a piece of paper. The anode and cathode will be secured within the cardboard then placed over the beaker with the cardboard supporting it. The crocodiles will be clipped on to the appropriate ends (negative to cathode and positive to anode). The power will be then turned on at 2 volts for a period of 3 and half minutes. Once this is done the anode and cathode will be blown dry with a hair dryer carefully for as not to spill any of the copper. The anode and cathode will then be weighed. Once this is done the experiment will be done for 4volts, 6volts, 8volts, 10volts each voltage will be tested three times. Results Test 1 Before After Change Voltage (v) Anode (g) Cathode (g) Anode (g) Cathode (g) Anode (g) Cathode (g) 2 0.63 0.77 0.62 0.78 0.01 0.01 4 0.62 0.78 0.60 0.80 0.02 0.02 6 0.60 0.80 0.59 0.84 0.01 0.04 8 0.59 0.84 0.57 0.88 0.02 0.04 10 0.57 0.88 0.54 0.96 0.03 0.08 Test 2 Before After Change Voltage (v) ...read more.

Conclusion

I believe this to be because of carelessness while weighing the anode and cathode as copper shards fell off the cathode. While trying to put the electrodes back into the cardboard we were unable to keep them the same distance apart due to the electrodes becoming more and more bent. The apparatus, such as the voltmeter, which is quite old and also may not be perfectly calibrated, could have caused other errors. Also the scales, which only show the mass to 2 decimal places, could have caused problems the rest of the digits in the weight are cut off with out rounding. Therefore this experiment could have been made more accurate by using lower current values, with the same size and separation of electrodes, controlling the voltage so that the temperature is constant, and using a more accurate voltmeter and a balance which rounds the other decimal places. I could have conducted the experiment differently by letting the copper dry naturally this will have prevented accidentally dropping the copper, which will have caused an error in measuring the weight. I could also look further in to this type of test by seeing if temperature of the solution could affect it. This may give me evidence that the temperature also affects the weight. I would keep the voltage at a fixed 8 volts then try heating the solution at 10-Celsius intervals. Then I could conduct the experiment the same as the one I have just done. Richard Thompson Chemistry Coursework 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

## Here's what a teacher thought of this essay

4 star(s)

This is a good experiment write-up. It has produced a good set of results and given valid reasons why the method was 'careless'. The evaluation was well done and gave excellent suggestions on altering it for next time. 4 Stars.

Marked by teacher Louise Star 21/06/2013

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

# Related GCSE Changing Materials - The Earth and its Atmosphere essays

1. ## GCSE Chemistry - Electrolysis Coursework

Cu2+ + 2e- At the cathode (-): Cu2+ + 2e- (r) Cu The copper at the anode releases copper ions and electrons, which float in the solution towards the cathode, where the copper ions and electrons deposit copper onto the cathode.

2. ## Factors affecting mass of copper transferred in Electrolysis of aqueous copper sulphate

atoms at the negative electrode the same number of copper atoms become ions at the positive electrode. So the overall number of copper ions in the solution remains unchanged. I can predict the mass of copper that will be added to the cathode and think that it should be proportional to the charge using the principles of Faraday's law.

1. ## Importance of electrolysis in our daily lives

After enough metal is deposited, by further machinery it can provide the exact shape wanted. ELECTRIC CELL One of the most common used every day object, the battery cell, uses the electrolysis for voltage difference. It essentially reverses electrolysis. It is made by placing two different metals in contact with an electrolyte.

2. ## The Electrolysis Of Copper Sulphate Solution Using Copper Electrodes

The rest are cut of with out rounding. Therefore this experiment could have been made more accurate by using lower current values, with the same size and separation of electrodes, controlling the current so that the temperature is constant, and the current more accurately controlled, and using a more accurate ammeter and a balance which rounds the other decimal places.

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

Change in Current Aim: To investigated how the rate of electrolysis is affected when changing the current in the circuit. Hypothesis: Michael Faraday's first law of electrolysis states: "The mass of any element deposited during electrolysis is directly proportional to the number of coulombs of electricity passed" This tells us

2. ## Investigate whether voltage affects the rate of electrolysis?

that is going through the circuit the quicker the chemical change will happen. The weight of the cathode will increase and the anode will decrease in weight. Apparatus In the experiment we will need 200ml of Copper sulphate, 2 copper electrodes about 1cm wide and 7cm long, electronic leads with

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

Graphite electrodes will be used throughout the experiment since they are inert, to ensure that there is no breakdown and no loss of mass. Electrode distance apart If the electrodes were a different distance apart from each other, the molecules would have to travel further perhaps resulting in a drop in current.

2. ## Investigating The Reactivity Of The Metals Iron, Magnesium, Zinc, Copper And Calcium And Their ...

If I look at the results for zinc and iron from my secondary source it is clear to see that both metals displaced the same number of solutions. From looking at my results I found zinc was more reactive than iron but only by a few seconds.

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