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stargazer
Apr3-04, 08:51 PM
Hi. I would very much like to know how to calculate the enthalpy change of a neutralization reaction, for example, NaOH(aq) and HCl(aq).
Thank you very much.
himanshu121
Apr4-04, 12:01 AM
Hi. I would very much like to know how to calculate the enthalpy change of a neutralization reaction, for example, NaOH(aq) and HCl(aq).
Thank you very much.
Strong acid + strong base has an enthalpy of neutrailzation = -13.7 Kcal
which is the case here
I get a different answer based on some data tables I have.
http://myfiles.dyndns.org/datasheets/chem_enthalpy1.jpg
http://myfiles.dyndns.org/datasheets/chem_enthalpy2.jpg
Energies are in KJ
delta H = [water + sodium chloride] - [hydrogen chloride + sodium hydroxide]
delta H = [-285.8 - 411.2] - [-92.3 - 425.6]
delta H = -179.1 KJ / mol
Thats about -43 Kcal / mol
Start from the standard elements in their most stable state at standard conditions. Unless the enthalpy of formation for each compound is provided to you already, it can be a bit complex. Here is an example...
http://groups.msn.com/GeneralChemistryHomework/general.msnw?action=get_message&mview=0&ID_Message=116&LastModified=4675466454162512526
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