Celery stalks immersed in a 0.2 M solution of NaCl for 3 hours become limp and soft. Similar celery stalks immersed in fresh water for 3 hours become stiff and hard. What can be deduced about the celery cells based on this information?

The celery cells are hypertonic to freshwater but hypotonic to 0.2M solution of NaCl

Explanation:

A hypertonic solution is one that whose concentration is more than that of the sap of the cell placed in it while a hypotonic solution has lesser concentration compared to the cell sap.

When the surrounding solution of a cell has more concentration than the cell sap, water molecules moves from the cell to the surrounding solution until equal concentration is established between the outer and the inner solution. The cell lose water and become flaccid. Such cell is said to be hypotonic to the surrounding solution.

On the other hand, when the surrounding solution has lower concentration than the cell sap, water moves from the surrounding solution into the cell and as a result, such cell becomes turgid. The cell is said to be hypertonic to the surrounding solution.

Water moves from the cell sap to the surrounding 0.2M NaCl solution, meaning that celery cells are hypotonic to 0.2M NaCl. On the other hand, water moves from surrounding freshwater into the cell, meaning that celery cells are hypertonic to freshwater.