Aim: Determine the enthalpy of combustion for a mixture of alcohol and gasoline, and its effectiveness as a fuel. Determine the most effective proportion of alcohol andgasoline considering ethanol avoids the effects of global warming but gasoline has a greater enthalpy of combustion so the addition of ethanol to the mixture would make it have a lower enthalpy ofcombustion.
Complete combustion of ethanol forms carbon dioxide and water vapor:
Complete combustion of octane forms carbon dioxide and water vapor.
[pic]The experiment has to take into account that it is only possible if the engine is designed or modified for that purpose. The ratio of gasoline to ethanol has to be significantly different; normally theproportion is 10% alcohol 90% gasoline. The experiment would not be possible if only ethanol was used. When analyzing the best proportion of each component take this into account. The benefit of usingalcohol is that it reduces the amount of carbon dioxide produced during the combustion; hence it will reduce global warming effects. The proportion would greatest amount of ethanol is the best toavoid pollution and the effects of global warming but this does not guarantee it is going to be the mixture would the highest enthalpy of combustion. To increase the benefits of the use of ethanol,ethanol could be acquired through fermentation. In this experiment ethanol was not acquired from fermentation but from a drugstore.
Variables: Independent: amount of [pic]and [pic][pic]
Dependent:energy, enthalpy of combustion
Controlled: amount of water, heat loss
-Weight a 250[pic]measuring cylinder.
-Using a measuring cylinder of 250[pic]record 200[pic] ofwater and place it in a beaker. Weight the beaker and the water.
-Substract the mass of the beaker and the water from the value of the mass of the beaker to get the mass of water.