Which is the lowest propane vapour pressure value listed in the data?

Which is the lowest propane vapour pressure value listed in the data?

• A. 172.0 psig
• B. 138.4 psig
• C. 149.0 psig
• D. 10.7 psig

Answer: (D)

Vapour pressure is the pressure at which propane vapor is in equilibrium with liquid propane at a given temperature. When you look at a data set, you find the lowest vapour pressure by picking the smallest numerical value listed. In the data given, 10.7 psig is the smallest number among the options, so it represents the lowest propane vapour pressure value. Remember that psig means gauge pressure, i.e., pressure above atmospheric pressure, so a lower numerical value indicates a lower vapor pressure at that temperature.

Vapour pressure is the pressure at which propane vapor is in equilibrium with liquid propane at a given temperature. When you look at a data set, you find the lowest vapour pressure by picking the smallest numerical value listed. In the data given, 10.7 psig is the smallest number among the options, so it represents the lowest propane vapour pressure value. Remember that psig means gauge pressure, i.e., pressure above atmospheric pressure, so a lower numerical value indicates a lower vapor pressure at that temperature.