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(n) solution.

hypertonic solution

Explanation:

Hypertonic solution -

It is the solution, with more amount of solute than the solvent , is known as hypertonic solution.

Now, is some substance is immersed in such solution , the substance gets shrinked , because , the solvent from the substance moves out of it and moves to the hypertonic solution.

Hence, the pickles gets shrinked up , as they put in a hypertonic solution.

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.