Methods of Enthalpy

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Michael Lee 2I
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Methods of Enthalpy

Postby Michael Lee 2I » Fri Jan 12, 2018 5:55 pm

Are we going to have to use more than one method of finding the enthalpy in any problem?

Swetha Sundaram 1E
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Re: Methods of Enthalpy

Postby Swetha Sundaram 1E » Fri Jan 12, 2018 5:57 pm

I think we have to use different methods depending on what we're given in the problem.

ConnorThomas2E
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Re: Methods of Enthalpy

Postby ConnorThomas2E » Fri Jan 12, 2018 9:34 pm

I think that he will give you a problem and based on the information he gives you, you will have to use a certain method to find the enthalpy. So I would make sure to know the various methods to calculate the enthalpy.

Dylan Mai 1D
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Re: Methods of Enthalpy

Postby Dylan Mai 1D » Fri Jan 12, 2018 9:45 pm

There are 3 methods we know of right now correct?

Varsha Sivaganesh 1A
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Re: Methods of Enthalpy

Postby Varsha Sivaganesh 1A » Fri Jan 12, 2018 9:48 pm

Dylan Mai 1D wrote:There are 3 methods we know of right now correct?


Yes! The first method is using Hess's method, the second is using bond enthalpies, and the third is using standard enthalpies of formation. So it just depends on what information the question gives you.

Susie Lee 2I
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Re: Methods of Enthalpy

Postby Susie Lee 2I » Sat Jan 13, 2018 11:05 am

Hess's Law (method 1) is a state function, which means it must be additive. The enthalpy change at each step of a multi-step reaction can be added to give the total enthalpy change. Bond enthalpies (method 2) are always positive and endothermic. The reactants (bonds broken) require energy, and the products (bonds formed) release energy.

Naana Boateng 1I
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Re: Methods of Enthalpy

Postby Naana Boateng 1I » Sat Jan 13, 2018 4:32 pm

Possibly, it depends on the type of question that Lavelle puts on his test, and whether or not there will be an A, B or C. Just be prepared for anything at this point.

aaron tang 2K
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Re: Methods of Enthalpy

Postby aaron tang 2K » Sun Jan 14, 2018 5:30 pm

It honestly depends on the question because there are 3 methods of enthalpy. 1. Hess' Method 2. Bond Enthalpies 3. Standard Enthalpies of Formation

AnuPanneerselvam1H
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Re: Methods of Enthalpy

Postby AnuPanneerselvam1H » Sun Jan 14, 2018 7:35 pm

Yes we learned three methods. The first one involves Hess's Law, the second one uses bond enthalpies, and the third one uses standard enthalpies of formation. The method you use depends on the information given.


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