In an evacuated vessel of capacity 110 litres, 4moles of Argon and 5 moles of `PCI_5` were introduced and equilibrium at `250^@C`. At equilibrium , the total pressure of the mixture was found to be 4.678 atm. Calculate the degree of dissociation `(alpha) "of " PCI_5 and K_p` for the reaction, `PCI_5 hArr PCI_3 +CI_2` at this temperature.

Explanation

To solve the problem, we will follow these steps:

### Step 1: Determine the Initial Conditions
- We have 4 moles of Argon (Ar) and 5 moles of PCl5 in a 110-liter evacuated vessel.
- The reaction is:
\[ \text{PCl}_5 \rightleftharpoons \text{PCl}_3 + \text{Cl}_2 \]
...