Question

The grain density (of solids only) and bulk density (solids + voids) of a sandstone sample are 2.7 gm/cm³ and 2.3 gm/cm³, respectively. The total porosity (in %, correct to two decimal places) of the sample is ...........

Hint:

Total porosity is a measure of the void space in a rock or sediment and can be calculated using the grain density and bulk density.

Answer 1

Correct Answer: 14

Step 1: Use the formula for porosity.
The total porosity \( \phi \) is given by the equation: \[ \phi = \frac{\text{Grain density} - \text{Bulk density}}{\text{Grain density}} \times 100 \] Substitute the given values: \[ \phi = \frac{2.7 - 2.3}{2.7} \times 100 = \frac{0.4}{2.7} \times 100 = 14.81% \] Thus, the total porosity of the sample is 14.81%.