Question 2


Asoil sample was collected using a tube 5 cm long and 5 cm indiameter. The wet soil sample

Weighs165.9 g. After oven drying the mass of the sample was 151.2 g. Thesoil grains are made

ofmineral quartz with grain density of 2.65 g/cm3.

(a)Compute the volumetric soil water content (volume of water divided byvolume of sample),

thewet bulk density of the soil (mass of wet soil divided by volume),and the dry bulk density.

Volumeof water in soil= Initial wet soil sample weight โ€“ weight of soilsample after drying

=165.9 โ€“ 151.5 = 14.4

14.4/151.2= 0.09524

wetbulk density of the soil = mass of wet soil /volume

165.9/ 14.4= 11.52g/cm3

Drybulk density of the soil = Mass/ Volume

=151.2g/57cm3 = 2.65g/cm3

(b)Compute the porosity of the sample (volume of pores divided by totalvolume).

Volumeof tube = 0.098125 cm3

Volumeof soil= Mass/ Density

151.2g/2.65g/cm3 = 57cm3

=0.098125/ 57 x 100 = 0.17 %