Question

A ring 10cm in diameter and 6.5cm is driven into the ground, excavated, trimmed flush with the ends of the ring, and weighed. The moist soil plus the ring were found to weigh 924.50. The ring alone weight 140.1. Calculate the volumetric after drying overnight at 105 degrees C, the soil plus ring weighed 727.2g. Calculate the volumetric water content of this sample.

Answer 1

Weight of ring alone = 140.10 g.

Wt. of ring + soil + water (moisture) = 924.50

140.10 + soil + water (moisture) = 924.50

soil + water (moisture) = 924.50 - 140.10

soil + water (moisture) = 784.40 g ............(1)

But drying over night at 105 oC (above B.P of water) will evaporate all the water moisture and left over will be just soil and ring.

On heating ovrnight,

Soil + ring = 727.20 g

Soil + 140.10 = 727.20

Soil = 727.20 - 140.10

Soil = 587.10 g.

Using this value in eq.(1) we get,

587.10 + Water (moisture) = 784.40

Water (moisture) = 784.40 - 587.10

Water (moisture) = 197.30 g.

Mass of water = 197.3 g.

As density of water is 1g/mL (approximately)

Volume of water = 197.3 mL

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