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Topic: Calculating theoretical temperature change of a reaction..  (Read 7450 times)

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Offline djones82

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Calculating theoretical temperature change of a reaction..
« on: December 10, 2012, 11:06:32 AM »
Have been trying to calculate the theoretical temperature rise when adding 124kg of Glacial Acetic Acid to 262.5kg of 50% KOH. Have an answer but have 0% confidence in it!!

Using ΔH=m.C.ΔT and having seen that the limiting reactant is Acetic Acid (this could be my first mistake) I have a entropy for the complete equation of -100.3kJ/mol.

This equates to 2064.95mol of Acetic Acid and therefore 207114kJ for the reaction.

Rearranging the equation above with 2.04 for the specific heat capacity I get a theoretical temp increase of 263 degrees....!

Please don't laugh at me!

Offline fledarmus

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Re: Calculating theoretical temperature change of a reaction..
« Reply #1 on: December 10, 2012, 03:54:48 PM »
Hmm, pouring a concentrated acid (even a weak acid) into a concentrated strong base, a huge increase in temperature doesn't sound unreasonable. Of course, with one that large, you have to figure the energy of evaporation of what little solvent you have as well.

Just a first impression - I haven't checked the math.

Offline curiouscat

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Re: Calculating theoretical temperature change of a reaction..
« Reply #2 on: December 11, 2012, 12:52:12 PM »
Using ΔH=m.C.ΔT and having seen that the limiting reactant is Acetic Acid (this could be my first mistake) I have a entropy for the complete equation of -100.3kJ/mol.

Entropy or Enthalpy?

Offline curiouscat

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Re: Calculating theoretical temperature change of a reaction..
« Reply #3 on: December 12, 2012, 06:43:44 AM »
Using ΔH=m.C.ΔT and having seen that the limiting reactant is Acetic Acid (this could be my first mistake) I have a entropy for the complete equation of -100.3kJ/mol.

Can you provide your data / sources for this part?

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