The rate at which sublimation occurs is referred to as what?

• A. Vapor Pressure
• B. Sublimation rate
• C. Heat Transfer
• D. Vapor Density

Answer: (B)

Sublimation is the process where a solid changes directly into a gas. The rate at which this change occurs is the sublimation rate, which tells you how fast molecules leave the solid surface and enter the vapor phase. Vapor pressure is the equilibrium pressure exerted by the vapor above the solid at a given temperature—an indicator of how readily sublimation tends to occur, but not the rate itself. Heat transfer describes energy moving into or out of the substance and can drive sublimation, but it isn’t the rate of the transition. Vapor density is the amount of vapor present per volume, a property of the gas rather than the speed of its formation. So the rate at which sublimation occurs is exactly the sublimation rate.