Ammonium hydrogen sulfide NH4HS(s) decomposes on heating according to the reaction NH4HS(s) ↔ NH3(g) + H2S(g) At 25 °C the equilibrium cnstant of the reaction is Kp = 0.11. What is the total pressure at that temperature in a flask that was initially partially filled with a sizeable amount of NH4HS(s)?

0.66atm

Explanation:

Based on the reaction:

NH₄HS(s) ↔ NH₃(g) + H₂S(g)

The equilibrium constant, Kp, is defined as:

Kp = 0.11 =

As moles of gas produced for NH₃(g) and H₂S(g) are the same, it is possible to write:

That means pressure of NH₃(g) is 0.33atm and H₂S(g) is, also, 0.33atm. Thus, total pressure is:

0.33atm×2 = 0.66atm