Preferable Method?

Moderators: Chem_Mod, Chem_Admin

Helen Mejia 1I
Posts: 67
Joined: Fri Sep 28, 2018 12:24 am

Preferable Method?

Postby Helen Mejia 1I » Sun Jan 27, 2019 6:41 pm

Since there are 3 methods can we use any in all the problems? Or is there a method that is more accurate than the other two depending on the question being asked?

Lexie Baughman 2C
Posts: 30
Joined: Sat Oct 06, 2018 12:16 am

Re: Preferable Method?

Postby Lexie Baughman 2C » Sun Jan 27, 2019 6:47 pm

The only thing Dr. Lavelle said about accuracy was that using bond enthalpies was the least accurate method because the values found in the table are an average calculated from many different compounds. Because of this, I think the other two methods are preferred and can be used interchangeably.

Raquel Ruiz 1K
Posts: 30
Joined: Tue Nov 14, 2017 3:02 am

Re: Preferable Method?

Postby Raquel Ruiz 1K » Sun Jan 27, 2019 6:54 pm

Usually Hess's method is a little bit more accurate because you won't have to write down all the bond enthalpies in an equation and keep track of the enthalpy change. With Hess's method you can just add the equations together change the moles and reverse the equations when necessary and at the end add or subtract to get the enthalpy change. Just make sure when you reverse an equation when using Hess's method you have to make sure to change the signs to a negative or a positive depending on the original value of Delta(H) for the corresponding equation.

Jocelyne Milke 1G
Posts: 73
Joined: Fri Sep 28, 2018 12:25 am

Re: Preferable Method?

Postby Jocelyne Milke 1G » Sun Jan 27, 2019 9:33 pm

I think it also depends on what information is given in the problem so one method might be easier to use for a specific problem.


Return to “Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)”

Who is online

Users browsing this forum: No registered users and 2 guests