Ammonium Iodide dissociates reversibly to ammonia and hydrogen iodide:

NH4I (s) ⇋ NH3 (g) + HI (g) Kp = 0.215 at 400°C

Calculate the partial pressure of ammonia at equilibrium when a sufficient quantity of ammonium iodide is heated to 400°C.

A. 0.103 atm

B. 0.215 atm

C. 0.232 atm

D. 0.464 atm

E. 2.00 atm

The partial pressure of ammonia at equilibrium when a sufficient quantity of ammonium iodide is heated to 400°C Is 0.103 atm.

The correct option is A.

Explanation;

NH4I (s) ⇋ NH3 (g) + HI (g) Kp = 0.215 at 400°C

NH4I (s) = 0.215

NH3 (g) = 0.103

HI (g) Kp=0.112

Therefore = 0.103 + 0.112 = 0.215

Therefore the partial pressure of ammonia at equilibrium is 0.103 atm