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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Brad on October 20, 2005, 03:11:56 PM

Title: How do I calculate total joules of heat from joules of electricity using a calor
Post by: Brad on October 20, 2005, 03:11:56 PM
My problem is that I have 2 test circuits using a capacitor as an input power supply.
Because of varying voltage and amperage from the cap and not having a simple equation (one that a engineer wannabe like myself can understand), I am having a problem with trying to calculate the amount of electricity converted to heat in joules inside the
Coffee cup calorimeter. The purpose of this testing is to verify the results of a multi-meter and the efficiency the 2 circuits.

The data I have to work with is:

Total joules provided by the capacitor  (337.5 joules at 15V)
(Yep it’s a big capacitor)

“Power under the curve” graphed out on graph paper giving temperature (temp. range from 75F to a peak of 132F) over time (approx. 45 min total).
From this, count total squares for each circuit. The one with the most squares produced the most power output and/or work.   
Again, from this how do I calculate joules of heat produced compared to joules of elec. used? Any help is appreciated.