During what state does nitrous oxide leave an E-cylinder as the tank is used?

Nitrous oxide leaves an E-cylinder in both liquid and gas states because of its unique physical properties. Initially, nitrous oxide in the E-cylinder exists primarily as a liquid under pressure, but as the gas is used and the pressure lowers, some of that liquid converts to gas, allowing both phases to be present simultaneously during use.

At higher pressures within the cylinder, the nitrous oxide remains in a liquid state. However, as nitrous oxide is drawn from the tank, it vaporizes and exits as gas while some portion remains liquid until the pressure drops significantly. This process continues as long as there is liquid nitrous oxide in the tank, which is why both phases are present when utilizing an E-cylinder of nitrous oxide.

In the context of the other options, only gas would imply that the tank would completely deplete the liquid and only release gas, while only liquid would suggest that no gaseous state is present during usage. The states of neither would dismiss the possibility of any material exiting, which is not applicable since both forms are indeed leaving the cylinder throughout the process of use.