Answer:
Ammonium bisulfide, NH4HS , forms ammonia, NH3 , and hydrogen sulfide, H2S , through the reaction NH4HS(s)⇄NH3(g)+H2S(g) This reaction has a Kp value of 0.120 at 25°C .
An empty 5.00-L flask is charged with 0.300 g of pure H2S(g) , at 25°C
Partial pressure of NH3 = 0.325 atm
Partial pressure of H2S = 0.368 atm
Explanation:
Temperature = 25 °C = 298 K
Volume = 5 L
Mass of H2S = 0.30 g
Moles of H2S = 0.30 / 34.08
= 0.0088
Using PV = nRT
Initial pressure of H2S = 0.0088 * 0.0821 * 298 / 5
= 0.043 atm
Kp = 0.120
(a). NH4HS(s) ⇄ NH3(g) + H2S(g)
Initial - 0.0 0.043
Change - + x + x
Equilibrium - x 0.043 + x
Kp = P(NH3) * P(H2S)
0.120 = x (0.043 + x)
x = 0.325 atm
Hence, at equilibrium:
Partial pressure of NH3 = 0.325 atm
Partial pressure of H2S = 0.043 + 0.325 = 0.368 atm
