Posted by chemmom on .
What is the change in the internal energy of the system when 1.243 mol of NH 3(g) is formed from N 2(g) and H 2(g) at 25 degrees C and 1.0 atm?

chemistry 
DrBob222,
N2 + 3H2 ==> 2NH3
delta E = q + w
I would look up delta H^{o}_{f}. Then
dHrxn = (n*dHoproducts)  (n*dHoreactants) and that will give you q.
W is p*delta V.
Use PV = nRT. You know n, R, P, and T; solve for V at the end. Knowing mols formed you can calculate mols N2 and H2 initially and calculate V initially.