Question

What is a solution that causes water to move out of a cell?

Answer 1

A hypertonic solution.

Explanation:

The term "hypertonic" solution refers to the concentration of the solute, which around the topic of cells is usually salt. Hypertonic means there is a high concentration of salt outside the cell, and the principles of diffusion tell us that the salt should then try to equalise the concentration gradient and move inside the cell. However, the salt is too large to fit through the cell's membrane, so instead we look at the "concentration" of water as that is one that can move in this situation.

Since there is more salt on the outside, there must be less water on the outside. Thus the water inside the cell moves to the outside through the pores in the cell membrane to equalise the concentration gradient (which we call osmosis).