Total porosity of a soil with 1.325 g/cc and 2.65 g/cc PD is

Soil porosity is the percent of total soil volume made up of pore space.
The total porosity is the total void space and as such includes isolated pores and the space occupied by clay-bound water.
$$\eqalign{ & {\text{Total porosity}} = \frac{{{\text{volume of voids}}}}{{{\text{total volume}}}} \times 100\% \cr & = \frac{{1.325}}{{2.65}} \times 100\% \cr & = 50\% \cr} $$