The diagram below illustrates an experimental set-up in soil analysis. Study it carefully and answer the questions that follow. (a) State the aim of the ill...

Answer Details

(a) Aim of the experiment

To determine the moisture content (and hence the organic matter content) of a soil sample by heating and drying it.

(b) Parts labelled I to IV

• I - Evaporating dish / crucible
• II - Soil
• III - Tripod stand
• IV - Bunsen burner

(c) Calculations

Mass of fresh soil = 60 g; mass of empty dish = 35 g; mass of dish + dried soil = 80 g.

(i) Weight of the dried soil

\[80\,\text{g} - 35\,\text{g} = 45\,\text{g}\]

(ii) Weight of water lost from the soil

\[60\,\text{g} - 45\,\text{g} = 15\,\text{g}\]

(iii) Percentage of water lost from the soil

\[\frac{15}{60} \times 100 = 25\%\]

(d) Three forms in which water exists in the soil

• Hygroscopic water
• Capillary water
• Gravitational water