Hydrocarbon + water carbon dioxide + Water (+ energy)
Methanol (CH3OH) would burn with a very clean flame, produce the least amount of energy as they have the least amount of hydrocarbons. This is because they only have 1 carbon atom, which combust in the shortest amount of time, out of the 4 other alcohols.
This is the complete combustion balanced equation showing methanol heated with carbon dioxide and water.
CH3OH + 11/2O2 CO2 + 2H20
Ethanol (C2H5OH) will burn with a very clean flame, produce the second least amount of heat energy as they have the second least amount of hydrocarbons. This is because they have only 2 carbon atoms in the 5-hydrocarbon chain, which will combust and be used in forms of heat energy really fast compared to Hexanol.
This is the complete combustion balanced equation showing Ethanol heated with carbon dioxide and water.
C2H5OH + 3O2 2CO2 + 3H2O
Propanol (C3H7OH) would burn with again a very clean flame producing heat energy between the ethanol and butanol alcohols. This is because the ethanol alcohol has 2 carbon atom and butanol has 4 carbon atoms, where as propanol has 3 carbon atoms producing more heat energy then propanol.
This is the complete combustion balanced equation showing Propanol heated with carbon dioxide and water.
C3H7OH + 41/2O2 3CO2 + 5H2O
Butanol (C4H9OH) would produce more heat energy then propanol and will combust longer than propanol as it has more hydrocarbon chains as it started off volatile before heating it, which then gets heated to crack the hydrocarbon chains to make them produce more heat energy.
This is the complete combustion balanced equation showing Butanol heated with carbon dioxide and water.
C4H9OH + 6O2 4CO2 + 5H2O
Hexanol (C5H11OH) would produce the most amount of heat energy as it has the most amount of hydrocarbon chains with the most carbon atoms, which crack into simpler forms to become more volatile, less viscous, more flammable and produce loads of energy in forms of heat.
This is the complete combustion balanced equation showing Hexanol heated with carbon dioxide and water.
C6H11OH + 81/2O2 6CO2 + 6H2O
Apparatus I will need:
· Copper calumeter,
· Water,
· Thermometer,
· Timer,
· Measuring cylinder,
· Alcohols, (sprit lamp)
· Bunsen burner,
· Retort stand,
· Clamp,
· Weighing balance,
Diagram:
I have drawn a diagram of what the experiment will look like seen below. I have chosen the best equipment given to me to carry out this investigation thoroughly.
Clamp
Thermometer
Retort stand
Copper calumeter
(with 150ml water)
Lighted Flame
Sprit lamp
Fair Testing:
To make the results reliable for each different alcohol I will be repeating the experiment to get an average from both results, I will also be keeping the same copper calumeter for each experiment as some might be thicker then others, which can cause a change in conductivity and results. I have also kept the same height of the copper calumeter the same so the tip of the flame would touch the bottom of the calumeter for each experiment knowing it will be a fair test. I will also have the same thermometer and the same amount of water in the calumeter. The thermometer would be fixed in the middle of the calumeter to give the reading of just the temperature of the water and not the conductivity of the copper calumeter.
Safety procedures
· Make sure you wear glasses through out the whole experiment,
· Make sure you have an apron on stopping your clothes from becoming dirty and getting in the way of lighting the alcohols,
· Make sure you don't sit next to the experiment incase the calumeter will fall, spilling hot water all over you,
· Make sure copper calumeter is tide tight to the metal rod,
· Make your you light the alcohol safely with your selves rolled up out of the way,
· And finally to make sure you put out the sprit lamp by putting on the glass top after use.
Method:
I plan to carry out this experiment by using all the safety issues and fair testing procedures to give me the most reliable and most accurate set of results on each alcohol. I plan to record the mass of the alcohol sprit lamp before the experiment and after, which would tell me how much alcohol was used in each experiment, which I can compare to other alcohols. I will then set up the experiment the same as the diagram, which I drew on the last page. I will place 150ml of tap water into the copper calumeter and clamp it to the retort stand, I will then place the thermometer in the centre of the water in the calumeter which will also be fixed to a clamp recording just the water temperature. This will give the most accurate set of results as the thermometer would be fixed the same for each experiment, where as if it wasn't fixed, and I was to hold the thermometer, or stir it, then some heat would be lost giving inaccurate results. I will then light the sprit lamp with a wooden splint wearing my safety glasses, and making sure the tip of the flame reaches the calumeter flask at the same time will be starting the stop clock recording the temperature of the water every minute. I will then do the same thing for each alcohol and repetition, giving me the most reliable and accurate results.
Looking at my preliminary results I decided to also change the time of when I will record the temperature gained by the water, from 2 minutes, to 1 minute, as the results I got in my preliminary results had a great change in temperature. This makes the experiment longer and harder as we only get one lesson to carry out the results and repetition of 5 different alcohols.
When I record the readings of the temperature I will be plotting down 5 readings for each alcohol giving me enough results to carry out a graph. I will then repeat the experiment for each alcohol, which will give an average of the two, I can then draw a graph of all 5 alcohols showing the temperature gained each minute that I can compare to the each other helping me to explain the results. I will also work out how much heat went into the copper calumeter flask from the alcohol burning by using the following formula:
Heat given out = mass of water x 4.2 x change in temperature
The units I will be using for the formula are listed below:
· Heat given out: Joule (J)
· Mass of water: Grams (g) 1cm3 = 1
· Change in temperature oC
I plan to record my results in the table seen below, which I also used in my preliminary work for each different alcohol.
Temperature in oC
Time (Min) Temperature 1st 2nd Results Average results Temp Gained
0
1
2
3
4
5
Mass before = 2nd results mass before =
Mass after = 2ndresults mass after =
Results
Temperature of water heated by METHANOL sprit lamp.
Temperature in oC
Time (Min) Temperature 1st 2nd Results Average results Temp Gained
0 25 25 25 0
1 29 32 30.5 4.5
2 38 40 39 8.5
3 46 48 47 8
4 55 57 56 9
5 64 66 65 9
Mass Lost Of Alcohol
1st Experiment's Mass Before of sprit lamp with Methanol = 190.22g -2.55g
1st Experiment's Mass After of sprit lamp with Methanol = 187.67g
2nd Experiment's Mass Before of sprit lamp with Methanol = 191.51g -2.23g
2nd Experiment's Mass After of sprit lamp with Methanol = 189.28g
Temperature of water heated by ETHANOL sprit lamp.
Time (Min) 1st Results 2nd results Average Temp Gained
0 25 25 25 0
1 31 30 30.5 5.5
2 42 37 39.5 9
3 52 45 48.5 9
4 64 53 58.5 10
5 72 60 66 7.5
Mass Lost Of Alcohol
1st Experiment's Mass Before of sprit lamp with Ethanol = 214.02g -2.28g
1st Experiment's Mass After of sprit lamp with Ethanol = 211.74g
2nd Experiment's Mass Before of sprit lamp with Ethanol = 165.68g -2.68g
2nd Experiment's Mass After of sprit lamp with Ethanol =163.3g
Temperature of water heated by PROPANOL sprit lamp.
Time (Min) 1st Results 2nd results Average Temp Gained
0 25 25 25 0
1 30 30 30 5
2 37 35 36 6
3 45 44 44.5 8.5
4 52 53 52.5 8
5 59 62 60.5 8
Mass Lost Of Alcohol
1st Experiment's Mass Before of sprit lamp with Propanol = 178.85g -1.35g
1st Experiment's Mass After of sprit lamp with Propanol =177.50g
2nd Experiment's Mass Before of sprit lamp with Propanol = 181.67g -1.32g
2nd Experiment's Mass After of sprit lamp with Propanol = 180.35g
Temperature of water heated by BUTANOL sprit lamp.
Time (Min) 1st Results 2nd results Average Temp Gained
0 25 25 25 0
1 31 33 32 7
2 39 40 39.5 7.5
3 50 49 49.5 10
4 60 60 60 10.5
5 69 68 68.5 8.5
Mass Lost Of Alcohol
1st Experiment's Mass Before of sprit lamp with Butanol = 164.82g -1.82g
1st Experiment's Mass After of sprit lamp with Butanol = 163g
2nd Experiment's Mass Before of sprit lamp with Butanol = 203.06g -1.39g
2nd Experiment's Mass After of sprit lamp with Butanol =201.67g
Temperature of water heated by HEXANOL sprit lamp.
Time (Min) 1st Results 2nd results Average Temp Gained
0 25 25 25 0
1 30 32 31 6
2 40 41 40.5 9.5
3 49 48 48.5 8
4 60 59 59.5 11
5 70 69 69.5 10
Mass Lost Of Alcohol
1st Experiment's Mass Before of sprit lamp with Hexanol = 182.41g -1.64g
1st Experiment's Mass After of sprit lamp with Hexanol =180.77g
2nd Experiment's Mass Before of sprit lamp with Hexanol = 159.90g -1.61g
2nd Experiment's Mass After of sprit lamp with Hexanol = 158.29g
Average temperature of water heated by 5 different alcohols measured in Degrees Celsius (oC).
Time (M) Methanol Ethanol Propanol Butanol Hexanol
0 25 25 25 25 25
1 30.5 30.5 30 32 31
2 39 39.5 36 39.5 40.5
3 47 48.5 44.5 49.5 48.5
4 56 58.5 52.5 60 59.5
5 65 66 60.5 68.5 69.5
This is a table of the amount of energy produced measured in joules by using the following formula: Heat given out = mass of water x 4.2 x change in temperature
CH3OH Methanol = 150 x 4.2 x 40 = 25200J
C2H5OH Ethanol = 150 x 4.2 x 41 = 25830J
C3H7OH Propanol = 150 x 4.2 x 35.5 = 22365J Odd Result
C4H9OH Butanol = 150 x 4.2 x 43.5 = 27405J
C5H11OH Hexanol = 150 x 4.2 x 44.5 = 28035J
Conclusion
Looking at my results on investigating into the combustion of a range of alcohols, I noticed a number of patterns. Looking at the results I can simply say what has been found out of the 5 different alcohols. I found out that the more hydrocarbons in the chain molecules in each alcohol, the more heat energy it will produce. This explains that the hexanol alcohol produced the most amount of energy as it had the most amounts of carbon molecules in the hydrocarbon chain out of the alcohols. These gives out loads of energy due to the big long chains of hydrocarbons cracking into simpler forms, which gives out more heat energy as there are more of them.
Looking at the bar and line graphs I noticed that there were many patterns, I noticed that the methanol alcohol with the least amount of carbon atoms in the hydrocarbon chain produced the least amount of energy excluding the odd result of the propanol alcohol. I noticed that the more carbon atoms in the alcohol the more heat it produces within the five minutes of readings. Looking at the sequence of the number of carbons in the alcohol, from the least, methanol, to ethanol, to propanol, to butanol, and to hexanol, is in order of the amount of heat energy produced, from the least to the most producing heat energy. This means that in order of the number of carbon atoms, from the least, to the most, increased in temperature on the final 5th minute reading, proving my original prediction was correct. Also looking at my scientific explanation I was correct for all the alcohols apart from propanol, as I got an anomalous result for the alcohol that could have been for a number of reason, which has also been mentioned in my evaluation.
Evaluation
Looking at the overall experiment and procedure used to find the results obtained, I thought that it was a good enough way to make me investigate the combustion of different alcohols. The results I got were near enough of what I would have expected from the alcohols used, which I mentioned in my conclusion. The only set of results I was unhappy with were the temperature gained by the alcohol propanol. This is because propanol looks to be an anomalous result. Propanol didn't follow the pattern in the sequence of the carbon atoms in the hydrocarbon chain as it's produced the least amount of heat, which was wrong, as methanol should have produced the least amount of heat energy as it had the least amount of carbon atoms. The Propanol alcohol should have produce a heat energy between the alcohols Ethanol and Butanol, which should have been about 26,000 joules, as Ethanol was 25,000 and Butanol was 27,000, so propanol should have been in between the two figures as Butonal had 4 carbon atoms and ethanol had 2, where as Propanol has 3 making the results in between the two. The odd result of the Propanol alcohol could have been an anomalous result for a number of reasons. It could have been because the tip of the fame might have not been touching the bottom of the copper calumeter flask, making the alcohol produce less heat to the water in the calumeter flask. It could have also been because of the flame as it might have been too small, which might have also gave a low temperature reading to heat the 150ml of water. The procedure of the experiment was good enough of finding out the energy gained from the indivdual alcohols, but changes could have been made to make the reliability of the results more accurate. This could have been done by using a better and more accurate thermometer, such as an electric thermometer, which have gave me a much more pin point set of results.
If I were to do this experiment again I would make a number of improvements or changes, one of my changes would have to be to use a Bunsen burner which would heat each alcohol and I could record its temperature gain every minute. This could be done by placing about 100ml of alcohol in a glass flask which would be heated with a Bunsen flame recording the results and comparing them to each other. I could also then measure the amount lost after recording the alcohol temperature after about 8 minutes, these results will be really high but we'll have a greater difference between each alcohol.
Looking at the experiment I did I thought we could have extended the results we achieved by using different flame lengths, this would have told us how much the alcohol uses its energy when the flame is increased. I could have also changed the amount of water in the copper calumeter, or even change the metal of the calumeter to change the conductivity.