All of these molecules are non-polar so their strongest IMF is dispersion forces. To rank their IMFs, remember that larger molecules exhibit stronger dispersion forces. Also, remember that vapor pressure is inversely proportional to IMF. So, to rank vapor pressure from smallest to largest, we simply rank the molecules from greatest IMFs to smallest IMFs.
a) change, but it is not possible to know if it will increase or decrease without more information.
b) decrease.
c) remain the same.
d) increase.
Answer: c) remain the same.
In a closed vessel containing water, the pressure is 18 torr. If we add more water to the vessel, this equilibrium pressure would
a) change, but it is not possible to know if it will increase or decrease without more information.
b) decrease.
c) remain the same.
d) increase.
Answer: c) remain the same.