The primary function of molecular membranes is the transport of ions and molecules into and out of cells—transport is directional and selective. the movement of molecules from areas of high concentration to areas of low concentration to gain energy is best described as

Explain what happens at the saturation point when adding salt to water at room temperature.

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.

Which is an example of a reversible physical change?