Final answer:
In passive transport, a charged solute moves spontaneously down its concentration gradient, from an area of higher concentration to an area of lower concentration.
Step-by-step explanation:
Passive transport refers to the movement of molecules or ions across the cell membrane without the need for energy expenditure by the cell. In passive transport, a charged solute will move spontaneously down its concentration gradient, from an area of higher concentration to an area of lower concentration. This movement is driven by the principle of diffusion, where particles tend to move to areas of lower concentration to achieve equilibrium.