# Is Delta H of formation the same for NH4NO3 Aqueous and in Solid Form?

by Austin
Tags: aqueous, delta, formation, nh4no3, solid
 Share this thread:
 P: 10 I am doing a project in Chemistry and I need to use Hess' Law to cancel two equations and if in one equation the NH4NO3 is solid and in the second one the NH4NO3 is aqueous. The equations are: 1: NH4NO3 (s) + HCl (aq) --> HNO3 (aq) + NH4Cl (aq) 2: NH4OH (s) + HNO3 (aq) --> H2O (l) + NH4NO3 (aq) I will find the heat of reaction for both of these reactions and use those values and Hess' law to find the Delta H of this reaction: HCl (aq) + NH4OH (s) --> NH4Cl (aq) + H2O (l) I am wondering if these procedure will work because I created this myself for the project we are doing and I don't know: 1. Whether these individual reactions work 2. Whether they add up to the overall reaction and whether that reaction even works. The part that is getting me stuck up is whether I can use Hess' law to cancel and aqueous version of NH4NO3 with a solid version. Your knowledge and advice is much appreciated! Thank you!
 Sci Advisor PF Gold P: 1,325 You have to take into account the enthalpy of solution. The Wikipedia entry http://en.wikipedia.org/wiki/Enthalp...ge_of_solution lists a few values, including that for ammonium nitrate. [Edit: I don't know why I focussed on ammonium nitrate, which is not what you asked about. See Borek's much better answer.]
 Admin P: 23,400 No such thing as solid NH4OH.

 Related Discussions Calculus 0 Atomic, Solid State, Comp. Physics 1 Chemistry 5 Biology, Chemistry & Other Homework 1 Chemistry 2