If a celery stick was placed in a beaker of water and another was placed in a beaker of salt solution, which liquid would make the celery flexible? Which liquid would make the celery crisp? How does osmosis relate to these results?
In the case of the celery in salt water, water would leave the cells and the stalk will become wilted.
In the case of the beaker with plain water, the water will move into the cells in the stalk. You would see this better if the stalk was already wilted.
Here is a video which discusses what happens to onion cells when placed into tap water and salt water.