During a ______ purge, the vessel is evacuated of its contents and filled with an inert gas.

During a ______ purge, the vessel is evacuated of its contents and filled with an inert gas.

• A. Boiling
• B. Siphon
• C. Vacuum
• D. Vent

Answer: (C)

Purging by evacuating the vessel and then backfilling with an inert gas creates a protective, low-reactivity environment. Pulling a vacuum removes air, moisture, and reactive vapors, and then introducing an inert gas fills the space with nonreactive gas, preventing air from re-entering and reducing the risk of oxidation, moisture reaction, or ignition. The other options don’t describe this combination of evacuating contents followed by backfilling with inert gas—boiling uses heat to remove substances, siphoning relies on gravity to move liquid, and venting releases gas to the atmosphere without establishing an inert atmosphere.

Purging by evacuating the vessel and then backfilling with an inert gas creates a protective, low-reactivity environment. Pulling a vacuum removes air, moisture, and reactive vapors, and then introducing an inert gas fills the space with nonreactive gas, preventing air from re-entering and reducing the risk of oxidation, moisture reaction, or ignition. The other options don’t describe this combination of evacuating contents followed by backfilling with inert gas—boiling uses heat to remove substances, siphoning relies on gravity to move liquid, and venting releases gas to the atmosphere without establishing an inert atmosphere.