This is the table of results I acquired from my preliminary experiments:
Safety Precautions
For the investigation I will take various precautions to minimise the possibilities of accidents. For all experiments goggles and aprons will be worn and at all times it will be made sure that ties are tucked in.
Apparatus
Stand & Clamp
Beaker
Thermometer
Varied Alcohol Burners (Methanol, Ethanol, Butanol and Propanol)
Method
First the apparatus is setup as shown in the diagram. The alcohol burner is then weighed and the distance between the lip of the burner and the base of the beaker is measured. The temperature is then taken and the burner is then lit and the stopwatch is set for two minutes. Once the two minutes has passed the burner is extinguished and is once again weighed to measure the amount of alcohol burned. The final temperature is taken and marked down. The same method is then repeated for each alcohol with the same distances between the lip and the base of the beaker.
Scientific Knowledge
The following is the method for the way in which energy is transferred when the four alcohols I am investigating are mixed with oxygen.
Methanol – 2CH3OH + 3O2 = 4H2O + 2CO2
Ethanol – C2H5OH + 3O2 = 3H2O + 2CO2
Propanol – 2C3H7OH + 9O2 = 8H2O + 6CO2
Butanol – C4H9OH + 6O2 = 5H2O + 4CO2
Results
B= before burning
A= after burning
The results above show that the higher in the series the alcohol is, the more efficient it is as a fuel for burning. Therefore Methanol had the lowest heat effect on the water and Butanol had the highest.
The graph confirms that the higher concentration of Carbon and Hydrogen atoms the more heat given off by the burner. I believe there is no real relationship in the amount of alcohol burned by each fuel as they all seem more or less the same. The line on the graph titled alcohol to water temperature change it is possible to clearly see the relationship stated before between the alcohols and the heat given off.
Conclusion
The higher the concentration of Carbon and Hydrogen molecules the more efficient the alcohol burns.
Evaluation
I believe that the experiment was carried out quite well with the limited amount of apparatus however I believe certain elements such as accuracy could be improved with higher tech equipment. However all safety precautions were taken and the results were taken as accurately as is possible.
There are many other aspects such as heat loss due to drafts in the lab which could knock the flame off course for a considerable amount of time so possibly a shield around the apparatus with air vents would contribute to more accurate results. If this experiment were carried out professionally I believe that it would be done in a sealed laboratory with a constant oxygen supply for the alcohol to burn in and all of the equipment would be high quality and electronic. For example an electronic thermometer. I believe there are a few anomalies in the results such as the third repeat for methanol when the temperature rose by 22 when previously it had only risen by ten and eleven degrees centigrade.
If the experiment were done professionally I also believe that many repeats would be made to get a far more accurate average for each alcohol.
I think there were some anomalies in my results and I do believe that some of the evidence is unreliable as the equipment was not constantly being monitored. The evidence could also be slightly unreliable as the equipment is not entirely accurate.
I believe that finally all of the experiments could have benefited from being done in a controlled laboratory.
