In my textbook, it says that the rate of vaporisation can be increased by (a) increasing the temperature or (b) reducing the pressure. I understand why an increase in temp can lead to more molecules breaking away from the liquid and entering the vapor state. More temp = more energy = more likely for the bonds to break and for molecules to become vapor. However, I don't understand why a reduction in pressure would have this effect. An increase in pressure is similar to an increase in temperature, isn't it? My logic is that an increase in pressure leads to more molecular collisions, which results in an increase in energy = more likely for bonds to break. Therefore, why does a reduction in pressure lead to an increase in vaporisation rate? Appreciate any help.