Answer
The volume of the anesthetic given to this patient is equal to 25 L
Work Step by Step
According to the Boyle's Law:
$$P_1V_1 = P_2V_2 \longrightarrow \frac{P_1V_1}{P_2} = V_2$$
$$V_2 = \frac{(5.0 \space atm)(5.0 \space L)}{1.0 \space atm} = 25 \space L$$
