Research question: What is the energy density of cyclohexane, and how does it compare to the energy density of normal hexane?
Variables:
Independent variable – The independent variable in this experiment will be the type of fuel that will be used. This will be either Hexane or Cyclohexane. Each type will be given to us and labelled so it will be quite simple to control this variable. This cannot be measured using any apparatus so the lab assistant must be entrusted in giving us the correct fuel
Dependent variable – The dependent variable in this experiment will be the change in temperature of water which will be placed above the burning fuel. This change in temperature will be measured using a thermometer which will be inserted inside the water. This change in temperature should vary depending on which fuel source is being used to heat it.
Controlled variable – The controlled variables in this experiment are as follows. The amount of water being heated, the starting temperature of water, the amount of fuel being burnt, and the duration of water heating. Most of these variables will be controlled using a measuring cylinder, stopwatch, and a thermometer.
Diagram:
Apparatus: * Beaker * Tripod, Gauze, Heat proof mat * Water (100 cm3) x 2 * Digital Thermometer * Fuel Burning Dish * Hexane, cyclohexane * Measuring cylinder * Stopwatch * Ignition source * Balance
Method: 1. Firstly, all the necessary apparatus was taken and set up according to the diagram. 2. The fuel burner was then filled with normal hexane (the amount has not yet been established but will be a controlled variable throughout the experiment). 3. The burner is then weighed on a balance and the initial mass is taken. Additionally, the initial temperature of the water is recorded using a thermometer. 4. Simultaneously, the fuel is ignited and the stopwatch is started. 5. After 90 seconds, the fuel