An investigation into the heat of combustion of five alcohols :: GCSE Chemistry Coursework Investigation

Alcohols : An investigation into the heat of combustion of five alcohols Planning ======== Introduction ------------ I am trying to determine the heat of combustion for the first five alcohols, which are; ethanol, propanol, butanol, pentanol and hexanol. I am trying to determine whether the amount of Carbon atoms on the molecule affects the heat energy given out by the molecule when burned. I believe that as the size of the molecule increases and the chain of carbons grows longer, then the heat energy given out will increase. I think that this is because when the molecule bonds are broken then they take in energy and then when the bonds are being made they give out energy. In a large molecule, more bonds are made so more energy is given out. Apparatus ---------  · Clamp stand  · Clamp  · Copper calorimeter  · Spirit burner  · Matches  · Thermometer  · Ruler  · Metal safety tray  · Top pan balance (digital scales)  · Measuring cylinder Method ------ I will need to collect all of the above apparatus and then put it together like in the diagram below. I will weigh the alcohol I will be burning and then put it under the copper calorimeter. I will use a measuring cylinder to measure out 100cm3 into the copper calorimeter. I will light my Flame, which will be 5cm under the calorimeter. I will use my thermometer to determine the temperature and then go up to 60 °c because that is how much I will change the temperature by. When the water has risen to 60 °c I will then put the lid on the spirit burner to extinguish the flame and then I will weigh the spirit burner again. By taking the new weight from the original weight I can then work out how much of the alcohol has been used. I will then repeat this experiment another four times with the other alcohols until I have done all five. I will repeat this twice to gain another set of results so I can compare them and identify trends and patterns consistent in both sets of results. How I will make my experiment a fair test ----------------------------------------- There is not really that much I can do to help make this experiment a fair test but I will; cool the copper calorimeter completely down by running it under cold water for a few minutes so that the water doesn't get warmed up by being in contact with it. I will also make sure that I have 100cm3 of water each time in the calorimeter. The temperature will always go up to 60 ° each time as well. I will also keep the height of the calorimeter at 5cm each time.