(M) A hydrogel is a unique polymer network that absorbs water. To determine the equilibrium swelling content, the gel is first weighed dry. Then it is sub-merged in water. Water is absorbed into the...

(M) A hydrogel is a unique polymer network that absorbs water. To determine the equilibrium swelling content, the gel is first weighed dry. Then it is sub-merged in water. Water is absorbed into the gel in a time-dependent manner. After one hour, the gel is removed, the surface is blotted dry, and the sample is reweighed. Absorption of water is not a chemical reaction. Answer the above questions for the properties of water and hydrogel during the process of determining the equilibrium swelling content.