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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 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.
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.
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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