Best Method of the 3 Given?
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Best Method of the 3 Given?
Given that there are 3 different methods to calculate the Delta H of a Reaction, which would be the most commonly used?
Re: Best Method of the 3 Given?
The normal method would be Method 1. It has the exact enthalpies and would give you the right answer. When doing bond enthalpies, its different because each molecules would have different and its jut an average. So method 1/3 are the best.
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Re: Best Method of the 3 Given?
I don't think there necessarily is a "best" method because it depends on what information you are given for each problem. In class, Method 2 (bond enthalpies) was described as the least accurate, so avoid it when you can. But as long as you know which method to use to apply what's given, you should be fine!
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Re: Best Method of the 3 Given?
I think method one is the most accurate since the enthalpies are given as exact for each reaction.
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Re: Best Method of the 3 Given?
Method 2 is the least accurate method but can be used if you are given bond enthalpies. For method 3 everything must be in a standard state and you will receive the standard reaction enthalpy. So I think if it doesn't specify to solve for the standard reaction enthalpy and just asks for the reaction enthalpy, use Method 1 which is also (Hess's Method). Basically use the information given to guide which method you will use.
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Re: Best Method of the 3 Given?
I don't know if there is a best method but I remember Dr. Lavelle specifically saying that using bond enthalpies was the least accurate method because these are calculated as averages across many different molecular configurations.
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Re: Best Method of the 3 Given?
Using bond enthalpies is the least accurate because the values used are averages, so they are not always reliable for the specific molecule in a given question.
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Re: Best Method of the 3 Given?
If you are asking for when to use what, it is obviously going to depend on the information you are given. However, as of like theoretical accuracy, bond enthalpies method is the least accurate because the value that are given to you are the average bond enthalpies, not exact. So it would be off compared to the other two methods
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