Ammonium nitrate dissolves in water via the following reaction:

Question

NH4NO3(s) → NH4+(aq) + NO3-(aq)
The bond energies of the compounds in the reaction are as follows:
NH4NO3 = 3040 kJ/mol
NH4+ = 1564 kJ/mol
NO3- = 1009 kJ/mol
How much total energy does the reaction have, and how will the environment change when the reaction occurs? Please show all of your work for credit

Answer 1

First, remember that bond energies are good for calculating reactions that are in the gaseous state. Apparently the author expects us to ignore that so here goes.
dHrxn = BEreactants - BE products
dHrxn = 3040 kJ - (1564 kJ + 1009 kJ)
dHrxn = +467 kJ/mol so the surrounds get colder.