When released from a refrigerated vessel, butane will:

When released from a refrigerated vessel, butane will:

• A. Transition from liquid to vapor
• B. Transition from vapor to liquid
• C. No change
• D. Condense to solid

Answer: (A)

Releasing a refrigerated liquefied gas from a storage vessel causes a rapid pressure drop that makes the stored liquid flash into vapor. Butane is kept as a liquid at cold temperatures; when vented to atmospheric pressure, it can no longer stay liquid at that temperature, so it boils and becomes vapor. This transition from liquid to vapor happens because heat from the surroundings is absorbed to provide the latent heat of vaporization. The result is a large amount of vapor released, with the liquid portion cooling as it vaporizes. It won’t condense to a liquid or solid under these conditions, and there will be a strong shift toward gaseous form upon venting.

Releasing a refrigerated liquefied gas from a storage vessel causes a rapid pressure drop that makes the stored liquid flash into vapor. Butane is kept as a liquid at cold temperatures; when vented to atmospheric pressure, it can no longer stay liquid at that temperature, so it boils and becomes vapor. This transition from liquid to vapor happens because heat from the surroundings is absorbed to provide the latent heat of vaporization. The result is a large amount of vapor released, with the liquid portion cooling as it vaporizes. It won’t condense to a liquid or solid under these conditions, and there will be a strong shift toward gaseous form upon venting.