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Topic: Heat of Reaction(Please Help)  (Read 4402 times)

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Saigan

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Heat of Reaction(Please Help)
« on: February 05, 2006, 05:31:52 PM »
Hey!  :bleh: Well, as you can see, this is my first post...

Alright...I've done HOURS..no wait, DAYS  :albert: of research trying to find this info. I'm doing a certain Science Fair project :book:, and I'm need the specific heat capacity of certain elements. I've done the experiments, and writen everything I could with what I have now. All I need is this part... Please *delete me*

What I need the specific heat capacity for:
I need it for Liquid Antacid Or otherwise know as Aluminum Hydroxide & Magnesium Hydroxide.

I also need the specific heat capacity of Squeezed Lemon Juice
The room temperature we used was 21 degrees centigrade

Well Thanks for your *delete me* :beerchug:
Sagain   :bounce:
« Last Edit: February 05, 2006, 05:41:54 PM by Saigan »

Offline Borek

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Re:Heat of Reaction(Please Help)
« Reply #1 on: February 05, 2006, 05:37:43 PM »
You will not find these, as the composition of both solutions is known only approximately.
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Offline arnyk

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Re:Heat of Reaction(Please Help)
« Reply #2 on: February 05, 2006, 05:43:43 PM »
Eh = mc(Tf - Ti)

E = heat energy
m = mass
c = specific heat capacity
T = change in temperature

I remember doing this with some metals in a lab using a hot plate.  You'll have to find the power of the hot plate to determine the amount of heat energy per time interval.  Then determine the temperature change after x minutes of the substance.  Then plug her all in.

Should be a crudely accurate number since alot of heat is lost if your container is a poor insulator.  It's an old high school physics lab I remember. :)  

OR how about googling it?  :D
« Last Edit: February 05, 2006, 05:45:38 PM by arnyk »

Saigan

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Re:Heat of Reaction(Please Help)
« Reply #3 on: February 05, 2006, 05:46:26 PM »
The bottle tells us that there are 200mg of aluminum hydroxide and 200mg of magnesium hydroxide per 5mL of solution. We used 100 liters of liquid so we know exactly how many grams of aluminum hydroxide & magnesium hydroxide we used.


For our purposes we are assuming the rest is water and other minor ingredients with heat capacities equal to water...

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Re:Heat of Reaction(Please Help)
« Reply #4 on: February 05, 2006, 06:03:15 PM »
What about lemon juice?

Explain what you trying to do, perhaps it will help in proposing some kind of solution.

But probably determining specific heat capacity by yourself will the best approach.

Note that while many solutions - especially those used in industry - have tables of densities, specific heat capacity and so on, these values were not measured for most, as they were never needed.
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