what happens when a cell is subjected to a solution where the water concentration is equal to that inside a cell? (isotonic solution)

When a cell is subject to a solution that is equal in water concentration as inside the cell, the movement of water via a process called osmosis will equalize and the solution is said to be isotonic to the cell. That means the amount of water entering the cell from the solution will equal the water exiting the cell; no net water movement.