Heats of Formation - prediction formula !!

[Flareman]

Being essentially a Mechanical engineer my Chemistry tends to be very rusty so I need some help please.

On a fairly regular basis I use Heat capacities and Heats of formation in my calcs. When I need to I can look up the requisite values but I do have some rough programming which I put together using Perry (Dobratz's eqn. and Meghreblian's recommendations which allows me to predict values of A, B and C in the equation
Ht capacity = A + BT + CT^2
using the chemical formation and bonding structure.

I also have tabulated values for A', B' and C' in the same (sort of) equation for Heat of formation. Can anyone point me towards a method to predict Heat of formation from the structure in the same manner as that I use for Heatcapacity. I'm sure that it has to be connected with the prediction I already have but I'm missing a key link somewhere.

Thanks for any help.

David

 

[phex]

perry's (7th ed.) has formula on page 2-348, for enthalpy of formation and gibbs energy of formation.

if you provide email adress, i'll send you the pages as well as the tables.

 

[Flareman]

phex
Thanks. I'd appreciate that.
Flareman_xs@Netzero.net will find me.
I'm still working with 5th Ed Perry. I suppose I should spring for an update.

David

 

[phex]

i'm sorry, you have to have patience till tomorrow =)

i could be sending you the complete chapter, but this is really large (18 mb). to extract the needed pages i have to get to my software at home... will send it tomorrow.

if, on the other hand, you want the whole 2nd chapter of perry 7, you're in for quite some waiting time

chris

 

[Flareman]

phex
I've been managing without it for a while, another day won't hurt.
I really do appreciate you spending the time on this for me. Don't overdo it though. Now I know where there's a source I can spend a lunch hour in the Library.

I started by trying to get my spreadsheets up-to-date and minimize the amount of extraneous look up and data entry and all of a sudden I find I'm knee deep in developing new ideas and approaches. At least it keeps me busy between coffee breaks.


David

 

[phex]

well, i think your effort in this forum (as much as i see of it) deserves SOME appreciation. and, as i do own the e-book version of perry 7, it is not as much trouble as it seems to be