Surrounding ions with water molecules is known as

Hydration  

Explanation:

In water, ions are surrounded by a sphere of water molecules called a hydration shell. The process of forming this shell is called hydration.

Explanation:

According to the law of dilution,

The given data is as follows.

    = 0.4782,     = ?

    = 0.025 ,     = 250 mL

Hence, we will calculate the value of as follows.

                          =

                          = 13.07

Thus, we can conclude that we need 13.07 mL 0.4782 M sodium thiosulfate solution using pipette.