Step-by-step explanation:
A solution which has higher concentration or more number of solute particles present outside a membrane than they are inside the membrane is known as a hypertonic solution.
A hypertonic solution is able for preservation of food as it tends to kill bacteria or limit their availability to reproduce.
Whereas a solution in which there is less solute present and more water than another solution is known a hypotonic solution.
When across a semipermeable membrane two solutions have the same osmotic pressure then this type of solution is known as isotonic solution.
When in a dilute solution, solvent molecules move through a semipermeable membrane into a more concentrated solution then it is known as an osmotic solution.
Thus, we can conclude that pickles are cucumbers preserved in a brine solution containing dill, alum, and salt. Cucumbers shrink to a fraction of their normal size in the pickle jar. This happens because of the relative salt content of the pickling solution, which is a hypertonic solution.