Consider the equilibrium: `LiCl - 3NH_3(s) = LiCl · NH_3(s) + 2NH_3(g)` with `K_p=9 atm^2` at `40^@C`. A 5-litre flask contains 0.1 mole of LiCl. `NH_3` . How many moles of NH, should be added to the flask at this temperature to drive the backward reaction practically to completion?

Explanation

To solve the problem, we need to analyze the equilibrium reaction and apply the equilibrium constant \( K_p \) to determine how many moles of \( NH_3 \) should be added to drive the backward reaction to completion.

### Step-by-Step Solution:

1. **Write the equilibrium expression**:
The given equilibrium is:
\[
LiCl \cdot 3NH_3(s) \rightleftharpoons LiCl \cdot NH_3(s) + 2NH_3(g)
...