A rigid, sealed vessel contains a sample of pure \(\text{I}_2\text{(g)}\) at an initial temperature of \(400\text{ K}\) and an initial pressure of \(1.20\text{ atm}\). The vessel is heated to a final temperature of \(800\text{ K}\). At this higher temperature, exactly \(50.0\%\) of the initial \(\text{I}_2\text{(g)}\) molecules dissociate into individual iodine atoms according to the following reaction:

\[\text{I}_2\text{(g)} \rightleftharpoons 2\text{I(g)}\]

Assuming ideal gas behavior, what is the final total pressure inside the vessel?