3. A soil sample has a volume of 75 cm3. After being saturated with water, it weighs 173.85 g. The sample is dried in an oven; the dry weight is 158.77 g. Assume the density of water is 1.00 g/cm. Find the porosity.

Porosity is the portions of the rock or a sample which is not occupied by solid material. And this void space is generally filled up by liquids, such as ground water. Porosity of a sample is measured on the basis of volume of the pore space in the total volume of the sample.

We have given a soil has volume = [tex]75cm^3[/tex]

Its saturated weight is 173.85 gram

Oven dried weight is 158.77 gram

Therefore the weight of the water present in the pore space = 173.85 - 158.77 = 15.08 gram

Density of the water = 1

The volume of the water present in the pore space is = 15.08 [tex]cm^3[/tex]

Now, Porosity = [tex]=\frac{V_V}{V_T}\times 100[/tex], here [tex]V_V[/tex] is volume of voids and [tex]V_T[/tex] is total volume

Porosity = [tex]\frac{15.08}{75}\times 100[/tex] = 20.107 %.