Question

Heterogenous equilibrium of ammonium
bisulfide. Ammonium bisulfide NH4HS forms ammonia NH3 and hydrogen sulfide H2S through the reaction NH4HS(s) arrows + H2S(g). This reaction has a kp value of 0.120 at 25 C. A 5.0-L flask is charged with .400g of pure H2S(g) at 25 C.

Evaluate the validity of the following statement. Give true or false anwswers and please explain so I can understand. I thought I did, but my answers are wrong:

No reaction occurs?
The reaction proceeds to the left?
The reaction proceeds to the right?
Q is greater than K?
Q is equal to 0?
The pressure of ammonia is zero?

What is the initial pressure of H2S(g) in the flask? Express answer numerically in atmospheres.
p = ________________atm

Answer 1

You need to explain the problem a little better. Is that the NH4HS system in equilibrium at 25C and the 5.00 L flask is charged with enough H2S to make 0.4 kg H2S? Or is that an additional 0.4 kg H2S is added to the equilibrium mixture? The way the sentence is structured says that you are placing 0.4 g H2S is a 5.00 L flask. Of course, no NH4HS can come out of that.
Initial pressure H2S is
moles H2S = 0.4/molar mass H2S.
Use PV = nRT and solve for partial pressure of H2S.