Subsoil is the layer of soil under the topsoil on the surface of the ground.
Given :
Number of moles , n = 36.25 mol .
Molarity , M = 1.25 M .
To Find :
The volume of water required .
Solution :
Moarity is given by :

So , 
Here , n is number of moles and M is molarity .
Putting all values in above equation , we get :

Therefore , volume of water required is 29 L .
Answer:
Dana filtered the sample and larger granules of the sample were left behind.
Explanation:
If a substance is pure, it will have a uniform composition throughout. It will not separate into particles of various sizes.
One of the characteristics of pure substances is that they are homogeneous. A mixture is definitely made up of particles of various sizes.
Since the particles was filtered and larger granules were left behind, the sample has been separated by a physical method (filtration). Only a mixture can be separated by physical methods. It is not a pure substance.