Chemistry - Chemical Equilibrium Question with Solution | TestHub
When NH2COONH4(s) is heated in an empty vessel at 300 K, the equilibrium NH2COONH4(s) ⇌ 2NH3(g) + CO2(g) is established and the total pressure of gases is 0.30 atm. When the solid is heated in the same vessel at 300 K in the presence of CO2(g), the partial pressure of CO2(g) at equilibrium is 0.40 atm. Which of the following is/are correct statement(s)?
Options:(select one or more)
Answer:
Solution:
First equilibrium: PNH3 = 2PCO2, so 3PCO2 = 0.30 atm PCO2 = 0.10 atm and PNH3 = 0.20 atm
Kp = (0.20)2(0.10) = 4.0 × 10-3 atm3
Second equilibrium: (PNH3)2 = Kp/PCO2 = (4.0 × 10-3)/0.40 = 0.010
PNH3 = 0.10 atm, so (a) is incorrect
The solid formed PNH3/2 = 0.05 atm of CO2, so initial PCO2 = 0.40 - 0.05 = 0.35 atm, so (b) is correct
Decomposition fell from 0.10 atm to 0.05 atm of CO2 formed, so (c) is correct
xNH3 = 0.10/(0.10 + 0.40) = 0.20, so (d) is correct
The correct options are (b), (c) and (d).
