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 illustrated experiment.
(b) Name the part labelled I, II, III and IV.
(c) A fresh sample of soil weighed 60 g. A container weighing 35 g was used to dry the soil. If both the soil and the container weighed 80 g after the experiment, determine the:
(i) weight of the dried soil;
(ii) weight of the water lost from the soil;
(iii) percentage of water lost from the soil.
(d) List three forms in which water exists in the soil.
Explanation
(a) Aim of the illustrated experiment
Determination of moisture content of a soil sample or organic matter content of the soil.
(b) Labelled parts in the illustrated experimentI – Evaporating dish/ crucibleII – SoilIII – Tripod standIV – Bunsen burner
(c) (i) Weight of dried soil
Weight of empty evaporating dish = 35g
Weight of dish + dried soil = 80g
Weight of dried soil only = (80 – 35)g
= 45g
(ii) Weight of water lost from the soil
(60 – 45)g
= 15g OR
(95 – 80)g
= 15g
(iii) Percentage of water lost from the soil
(d) Forms in which water exists in the soil
- Hygroscopic water
- Capillary water
- Gravitational water