Question

For the reaction 3NO(g) ⇌ N2O(g) + NO2 (g) at equilibrium, Kp = 1.3×10^18 . Exactly 0.025 atm of NO is introduced into a 1.00 L flask. What is the correct expression for Kp ?

Answer 1

Solution:- For the given balanced equation, the Kp expression is written as...

Kp = (pN₂O)(pNO₂)/(pNO)³

in this expression p stands for partial pressure. For example, pNO means partial pressure of NO.

Initially, 0.025 atm of NO are introduced. Let's say the change in partial pressure is X. Then, the ice table would be...

3NO(g) <-----> N₂O(g) + NO₂(g)

I 0.025 0 0

C -3X +X +X

E 0.025 - 3X X X

plugging in the equilibrium partial pressures in the Kp expression..

Kp = (X)(X)/(0.025 - 3X)³

Kp = ((X)²)/(0.025 - 3X)³

if we plug in the value of Kp also then...

1.3 x 10¹⁸ = ((X)²)/(0.025 - 3X)³