Title: Thermochemistry and
Purpose: Measuring the heat of neutralization and heat of combustion, with the combustion of
hydrocarbon fuel.
Procedure:
... [Show More] NaOH + HCl → NaCl + H2O ▲H= ? kJ/mol. We are using a coffee cup calorimeter
for this experiment; we have a thermometer and a cardboard lid. We are going to mix sodium
hydroxide and NaCl and we will be measuring the heat change as they come together, this will
be an exothermic reaction. We are going to mix the two solutions together. First, we must
determine the heat capacity of the calorimeter, this is how much heat the calorimeter will absorb.
We are going to take 50 mL of water and pour that in the calorimeter, there is a stopper on the
cardboard to suspend it from the cardboard. Then there is 50 mL of water, and the water bath is
set to 40 degrees, the water is set in the water bath, and we are going to let each of the waters sit
for about five minutes.
After give minutes we take the water out of the water bath and measure the temperature which is
38.0. The tap water in the calorimeter is about 22.8 degrees Celsius. We are going to pour the 50
mL of warm water into the calorimeter and then take a new temperature read. The new
temperature after 15 seconds is 29.6, 29.8 after 30 seconds, and 29.8 after three minutes.
The calorimeter is empty and dried out, we take 50 mL of HCl and pour it in the calorimeter and
then measure the temperature. In the NaOH we are going to monitor the temperature of each for
a few minutes, the temperatures need to be nearly identical. After the temperatures are set we
pour the NaOH into the calorimeter and stir it a bit and then track the temperature every 15
seconds for three minutes.
The diethylene-glycol has a reaction of C4H10O3 + 5O2 → 4CO2 + 5H2O. The organic compound
of C4H10O3 is HO-CH2-CH2-O-CH2-CH2-OH. The fuel value is 6020 cal/g (45%. We have a ring
stand with a copper pan and we are going to place our fuel source under the copper pan. Copper
conducts heat well. We are going to place water in the copper pan with cardboard with a hole
over it and we will use a thermometer to measure the temperature rise. First, we are going to
measure the mass of the fuel and the can in the balance before we burn it. We pour 500 mL of
water into the copper pot and place the thermometer with the carboard cover back over the
copper pot. We then light the fuel source and let it begin to heat up the water. You want the heat
to be a distance away from the pan, so it does not burn. The water is heating up quickly. We stir
the water with the thermometer a bit. The temperature rises so then we snuff out the flame and
stir the water a bit more to make sure it is nice and well mixed [Show Less]