Which term describes the amount of vapor present in a liquid–vapor mixture?

Which term describes the amount of vapor present in a liquid–vapor mixture?

• A. Vapor Content
• B. Vapor Quality
• C. Specific Humidity
• D. Absolute Humidity

Answer: (B)

Vapor quality is the fraction of the total mass in a saturated liquid–vapor mixture that is in the vapor phase. It is defined as x = m_v / (m_l + m_v), and it ranges from 0 (all liquid) to 1 (all vapor). This term describes how much of the mixture is vapor during phase change, such as in boilers or condensers. The other terms refer to moisture in air rather than a liquid–vapor mixture: specific humidity is water vapor per kilogram of dry air, and absolute humidity is water vapor per unit volume of moist air. Vapor content isn’t the standard descriptor for a liquid–vapor mixture, so vapor quality is the best choice.

Vapor quality is the fraction of the total mass in a saturated liquid–vapor mixture that is in the vapor phase. It is defined as x = m_v / (m_l + m_v), and it ranges from 0 (all liquid) to 1 (all vapor). This term describes how much of the mixture is vapor during phase change, such as in boilers or condensers. The other terms refer to moisture in air rather than a liquid–vapor mixture: specific humidity is water vapor per kilogram of dry air, and absolute humidity is water vapor per unit volume of moist air. Vapor content isn’t the standard descriptor for a liquid–vapor mixture, so vapor quality is the best choice.