# Comparing the Enthalpy Changes of Combustion of Different Alcohols

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Comparing the Enthalpy Changes of Combustion of Different Alcohols Introduction In this investigation I will set out to find the differences in the enthalpies of combustion of 6 different alcohols. These are methanol, ethanol, butan-2-ol, propan-1-ol, propan-2-ol and 2Methylpropan-1-ol. I can then find the variation between straight chain and branched molecules and isomers. Planning -------- Method ------ Carrying Out The Experiment To carry out the experiment, I will fill my calorimeter with 75g of water. It is important that this is accurate, as it is needed to find the enthalpy change. The calorimeter will be held up by a clamp, connected by a boss to a clamp stand so that heat can be applied without having to hold the calorimeter up myself. The calorimeter always needs to be the same distance away from the heatproof mat at the bottom. The calorimeter is made of copper and is a good conductor which means that most of the heat the copper absorbs will be passed onto the water inside it.I will then need another clamp stand, clamp and boss to set up a draft-extrusion system. This will be 3 heatproof mats which will surround the calorimeter, ensuring that as much of the heat as possible goes to the calorimeter and not its surroundings. I will then need to record the starting temperature, as this is needed to find the change in temperature. Now, I take the mass of the spirit burner I have so that I can calculate the amount of alcohol that was used during the combustion. I can now light it and let it burn. I will aim for a temperature change of 20°C. Once it reaches that temperature change, I will need to pull away the spirit burner and then record the final temperature of the water and also weigh the final mass of the fuel. I can then find out the change in temperature, which is the final temperature - the initial temperature. The mass of alcohol used can be calculated by the initial mass of alcohol used - the final mass