Investigation of the heat energy produced by combustion of various Alcohols
Aim:
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To investigate how different alcohols produce different amounts of heat energy through combustion. I will be heating water using different alcohols as fuels and measuring the amount of fuel consumed.
From working out how much fuel has been used I can work out how much bond energy has released from the molecules of the alcohol. From those results I will be able to say which alcohol is the best for combustion and which one is the worst to combust.
· A good fuel should produce a lot of heat energy and use a small amount of fuel. (economical)
· A bad fuel uses a lot of fuel and produces less heat energy.
(non-economical)
E=mc
E= Energy
M= mass of water
C= Specific heat
= Difference in temperature
Using this equation I will be able to find out which fuel gives out the most heat energy and use the least amount of fuel.
Variables
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During the experiments the water will be heated using different spirit burners containing different alcohols. I will be able to change different parts of the experiment. These are:
· Volume of water heated: Depending on how much water we use depends on how long it takes to heat up. If we heat a large volume of water it will take it longer to heat up, as there will be more molecules for the heat from the spirit burner to give energy to, it will take longer for the water molecules to get enough energy to loosen and break, so the reaction will be slower. If we only use a small volume of water the heat energy from the spirit burner will give the water molecules energy faster as there are will less of them so more heat energy per molecule, this means the bonds will loosen and break quicker so the reaction will be faster.
· Distance between spirit burner and Copper Calorimeter: The further the copper calorimeter is from the heat source the more heat will be lost into the surrounding atmosphere and not directed towards the water and the slower the reaction will be. If the pot is close to the heat source, more heat is directed to the water so will be heated faster. · The Alcohols: Different alcohols have different bond structures, some bonds needing more energy to break them than others, and some releasing more energy when they are broken.
· Temperature increase: I could change the amount the temperature has to rise before I record my results. This will only effect the amount of fuel used, so hasn’t got much relevance to the experiment.
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Tf-Ti). Next, subtract the initial temperature, 25 degrees from the final temperature, 29 degrees putting the change in temperature at 4 °C. To calculate the heat absorbed by the water in calorimeter, use the formula (q = mCΔT). Plug in 50 mL for (m), 4.184 J for (C) and 4 °C for the initial temperature (ΔT), then multiply.
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put in the pot. If the person knew if changing the volume of a substance will not change the boiling point, but only alter how much time it takes for the substance to reach the temperature. Then the person would know that it would be better to not put too much water in the pot, because it would take longer for the water to boil.
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The U.S. Department of Energy projects that if a mere 10% of automobiles nationwide were powered by fuel cells, regulated air pllutants would be cut by one million tons a year and 60 million tons of the greenhouse gas carbon dioxide would be eliminated. DOE projects that the same number of fuel cell cars would cut oil imports by 800,000 barrels a day which is about 13 percent of total imports.
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one gram of water by 1ºC. I chose to use water because it is safe,
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- Temperature was measured after and exact time i.e. 1 minute, 2 minutes, 3 minutes.