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Optimizing Ethanol's Heat Production |
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Table of Contents |
Discussions: There were two different sets of experiments performed in two different circumstances. The first set was performed with a pool of water around the burning ethanol in order to cool down the flame produced by ethanol and to provide a medium where heat could be consistently absorbed and the other was performed without a water surrounding. The reason this was implemented was in an attempt to slow down the decomposition of hydrogen peroxide into oxygen gas and water. Instead of a single burst of oxygen released due to high heat, a gradual release of oxygen was expected. This was observed as the final temperature of the hydrogen peroxide solution consistently had a higher temperature than the water solution. In the experiment where no water was surrounding the flame, it was observed that the temperature was too high and the hydrogen peroxide decomposed almost instantly (within the first minute or so) which is indicated by the high jump in temperature during the first minute of the burning. At a first glance at the final temperature of the solutions, one may see that the 100% ethanol solution was the most superior of all of the combinations of ethanol, water and hydrogen peroxide. However, by calculating the heat produced per mole by using the formula: Q = mCT, one may figure out how effective or ineffective hydrogen peroxide really is. By examining observation tables 1.3 and 1.4, it is easy to see that a mixture of ethanol and hydrogen peroxide is indeed more effective than both water and pure ethanol. Its use shines especially within 30 to 60 seconds of the burning of 75% ethanol to 25% hydrogen peroxide, recording a maximum of 3 times the heat produced by pure ethanol and 2 times the heat produced by water and ethanol at the same concentration. A general trend was that ethanol and hydrogen peroxide burned faster than ethanol and water. This was because the hydrogen peroxide produced oxygen gas that is required in a combustion reaction and sped up the combustion with the excess oxygen. Even though the burn time was lower, the solution of ethanol and hydrogen peroxide often had a higher final temperature indicating that more heat was given off in a shorter period of time. Another trend was that the heat produced per mole in the water and ethanol solution went down as the concentration of water increased. However, in the solution of ethanol and hydrogen peroxide, the heat produced per mole of the solution increased as the concentration of hydrogen peroxide increased. The highest heat released per mole was recorded in 75% ethanol and 25% hydrogen peroxide indicating that hydrogen peroxide is very useful in increasing the amount of energy produced by a fuel. Furthermore, during the experiment, a foul odour was given off during the burnings of ethanol and water and a watery yellow substance was left behind after the burning had completed. However, no such smell was given off during the burning of ethanol and hydrogen peroxide and the liquid that was left over was clearer and transparent. This indicates that hydrogen peroxide helps ethanol to burn more cleanly and reduces its waste materials.
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