Thermochem help!
N2(g) + 3 H2(g) -- 2 NH3(g) ΔH°rxn = -92.6 kJ/mol

1) If 3.0 moles of N2 react with 9.0 moles of H2 to form NH3, calculate the work done (in joules) against a pressure of 1.0 atm at 25°C.
___________kJ

2) What is ΔE for this reaction? Assume the reaction goes to completion.
__________kJ
This is the only question I am having trouble with! I need help on how to do this, I've spent alot of time trying to figure it out and now my brain is burned! Can someone help? Please and thank you :)

Question

Thermochem help!
N2(g) + 3 H2(g) --> 2 NH3(g) ΔH°rxn = -92.6 kJ/mol

1) If 3.0 moles of N2 react with 9.0 moles of H2 to form NH3, calculate the work done (in joules) against a pressure of 1.0 atm at 25°C.
___________kJ

2) What is ΔE for this reaction? Assume the reaction goes to completion.
__________kJ
This is the only question I am having trouble with! I need help on how to do this, I've spent alot of time trying to figure it out and now my brain is burned! Can someone help? Please and thank you :)

jfraser · Answer

if 1.0mol of N2 releases 92.6kj of energy, then 3 moles of N2 should release three times that much. 

assuming all the energy is used to do PV work, the energy release is equal to the work done. Since "no" energy is lost to heat, the DE and the work done are also equal