Hello,
The question is:
1 mole of nitrogen gas and 3 moles of hydrogen gas were added to a rigid 1 L container at 298 K and left to react. At equilibrium it was found that the concentrations of nitrogen, hydrogen and ammonia were 0.116 mol Lā1, 0.348 mol Lā1 and 1.768 mol Lā1 and the pressure inside the container was 55 bar.
1 mole of hydrogen chloride gas was subsequently added to the container and the system was left to re-establish equilibrium (hydrogen chloride gas reacts with ammonia gas to produce solid ammonium chloride).
What are the concentrations (or range of concentrations) of nitrogen, hydrogen, ammonia and hydrogen chloride once equilibrium has been reached for the second time?
I have attached the multi-choice answers.
So the 2 equations after HCl was added is:
N
2 + 3H
2 2NH
3HCl + NH
3 NH
4Cl
So after HCl is added the ammonia will react with it creating NH
4Cl. So therefore the N
2 and H
2 will increase forward reaction to balance the equilibrium. So A and C are ruled out. The ammonia will react to form NH
4Cl so B is also ruled out. Now I am left with D and E, I choose E since some NH
4Cl will dissociate back into HCl + NH
3. However, the answer is D. I can't think of any reason the HCl concentration would be 0, if HCl is 0 then the equilibrium constant for HCl and NH
3 is impossible.
[tex]Kc=\frac{1}{[HCl] [NH3]}[/tex]
Can someone give me a hint as to why the HCl concentration would be 0?
Thanks