In the following experiment, you will determine the heat of combustion* (DHcomb) for an organic compound. In order to do so, it is important for you to pay attention to the sign of the temperature change and to keep careful track of units. Remember this is a calorimetry experiment. The fundamental relationship that you will use is:
In this case qcal = Ccal x DTcal and qsys = DHcomb.
Now, make sure you have a worksheet, and follow the directions on it carefully. Think about what you are doing and you will be able to properly determine the heat of combustion of one of the compounds form the list below.
| * This simulated experiment actually generates your results as DHcomb. In reality, bomb calorimeters measure the change in energy of a reaction (DErxn). However, there is a simple relationship between DHrxn and DErxn. |
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| DE is the energy change that occurs in a container of fixed volume, DH is the energy change that occurs in an open container at constant pressure, R is the gas law constant (typically expressed as 8.314 J/Kmole in this equation), T is the Kelvin temperature, and Dng is the change in the number of moles of gas (Dng = moles gas product - moles gas reactant). | |