Which statement best distinguishes TVP and RVP?

• A. TVP is the rate of evaporation; RVP is actual vapor pressure
• B. TVP is actual vapor pressure; RVP is the rate of evaporation
• C. TVP and RVP are the same
• D. TVP is ambient pressure

Answer: (B)

Understanding how vapor behavior is described helps you see the difference between TVP and RVP. TVP stands for the actual vapor pressure—the pressure the vapor would exert when it is in equilibrium with the liquid at a given temperature. It is a specific, measurable pressure that reflects how much vapor is present at that temperature.

RVP describes the rate at which the liquid tends to vaporize under defined conditions. In other words, it reflects how quickly vapor forms from the liquid, rather than the steady pressure in equilibrium.

So the best way to distinguish them is: TVP is the actual vapor pressure in equilibrium, while RVP is the rate of evaporation. The other statements mix up these ideas or describe ambient pressure, which isn’t what TVP represents.