In hypotonic solution, what way does water move?

Hint: A solution is said to be a hypotonic solution when the concentration of solute outside the cell is higher than that of inside the cell. In terms of concentration water works as the factor of dilution. Thus we can say that for a hypotonic solution the solute has a higher water level than another solution or its surrounding solution. Water will flow to make an equilibrium between the solute and surrounding.

Complete answer:
With the help of tonicity we can easily explain that a solution is hypotonic, hypertonic and isotonic with respect to other solutions. Hypotonic solutions are those solutions whose solute concentration is much lower than that of surrounding solutions. Both solutions whether it is hypertonic or hypotonic want to become isotonic solutions. Thus isotonic solutions are those which have the same solute concentration. Thus in order to become an isotonic solution, for a hypotonic solution the water molecules will flow into the cell by the process known as endosmosis. Endosmosis can be defined as the movement of water molecules into the cell when a cell is placed in the hypotonic solution. Thus as the result of endosmosis the cell will swell up. Thus when we put raisin in the hypotonic solution the water enters into it and makes it swell.

Note:
Exosmosis is the reverse of endosmosis in which the water molecule moves from the cell and as a result the cell will completely shrink. As there is equilibrium in the chemical reaction, the condition of isotonicity is the same. To maintain the equilibrium between the solutions, the tonicity of the solution must be the same and thus refer to isotonic solutions.