Answer: The total pressure of the container will be 2.00 atm
Step-by-step explanation:
We are given:
Initial moles of phosphorus pentachloride = 1.00 atm
For the given chemical reaction:

By Stoichiometry of the reaction:
1 mole of
produces 1 mole of
and 1 mole of chlorine gas
So, 1.00 atm of
will also produce 1.00 atm of
and 1.00 atm of chlorine gas when the reaction goes to completion.
Total pressure of the container when the reaction goes to completion = 1.00 + 1.00 = 2.00 atm
Hence, the total pressure of the container will be 2.00 atm