This is how I accounted for the heat loss of the insulated container
used to contain water. After running the experiment with both sodium hydroxide
and ammonium nitrate, I repeated the experiment with lithium chloride. Lithium
chloride was used because the energy it releases when mixed with water is known
and could therefore be used to calibrate the measurement device. This gave me
three sets of data, one for each of the chemicals. For each of the data sets I
ran three trials. To correct the data, I needed to know the amount of energy unaccounted
for by the change in temperature. I used equation 1 to find this number.
Equation
1
E = amount of energy lithium chloride is known to give off
when it mixes with water (this number can be found by looking in the CRC Handbook of chemistry of physics. ∆T = is the change is temperature. c = specific heat of water. m = the total
mass. q = the amount of energy lost for
every degree of temperature change.
I then used equation 2 to find the amount of energy the
other chemicals released or absorbed. This equation was used instead of (E=mc∆T)
because it corrected for the energy lost to the container.
Equation 2
E = the energy that is released or absorbed. m = total mass.
c = specific heat of water. ∆T = is the change is temperature. q = the amount
of energy lost for every degree of temperature change (found using equation 1)
-Kyle
-Kyle
Note on notation: Usually "q" is reserved for "heat" in Joules. Here it is actually a heat capacity in J/K. We probably should have used "C" instead of "q".
ReplyDeleteI also note that no one has thanked you for this post even though they've used the explanation...
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