Earth Science (PHSC 101) Virtual Laboratory Experiment # 5:
Permeability of Dif
Earth Science (PHSC 101) Virtual Laboratory Experiment # 5:
Permeability of Different Earth Materials
Name: ________________________ Section: _______ Date: ______
Note on this virtual Lab Experiment
Read the introduction outlined below on principle, procedure and experimental materials, and try to understand as to how this virtual experiment would be conducted under real lab condition to generate the raw data supplied in the Table below. After clearly understanding the procedure and the formula for the calculations, enter calculated values in the blank columns and write brief discussions as per the guideline, and Submit it back in the Drop Box. Introduction
During rainfall most of the water that reaches the land surface will infiltrate or runoff. The balance between infiltration and runoff is influenced by factors such as the porosity and permeability of the surface materials, slope of the land, the amount and intensity of rainfall, and vegetation cover. After infiltration saturates the land and the ground contains all the water it can hold, runoff will begin to occur on the surface. The objective of this virtual experiment is to gain a better understanding on the permeability of different soil materials with different porosity and realize their influence on the movement of water underground, as well as to have a better insight as to how such experiments are being carried out to generate the theoretical data under real lab condition. Materials and Methods
Materials and Equipment
Graduated measuring cylinder Beaker Digital balance
Funnel Filter paper
Stopwatch
Different earth-material samples (three samples)
Procedure followed to generate the data on the Table below Properly folded filter paper is placed in a funnel and let the funnel stand with the bottom in an Erlenmeyer flask. Such setup is arranged in a set of three for running samples 1, 2 & 3 side by side. From each of the Earth materials supplied (sample 1, 2, & 3) 25g is weighed on a piece of paper, one at a time, and quantitatively transferred on to the filter paper in each of the funnels placed on the Erlenmeyer flasks. 50 ml of water is measured in a volumetric cylinder, one for each sample set. With the bottom of the funnel placed in the flask, the measured 50ml of water is slowly added, one at a time to each of the funnels containing the sample. A stopwatch is set on when applying the water starts in each case. The 50 ml of water in each case is poured until all is used, taking care not to add above the capacity of the filter paper in the funnel at a given moment, by allowing some time for the water to drain through before adding more water. After pouring the last drop from the cylinder, it is observed until all the water drains out of the funnel. The stopwatch is not stopped until the interval between two successive last drops is more than one minute. The stopwatch is stopped and the time in minutes (min) is recorded in the data table (seconds are converted to a fraction of a minute). Using the graduated cylinder, the amount of water drained into the flask was measured (in milliliters) for each of the samples, and values in ml is recorded in the appropriate column in the data table.
At the end of the experiment, the funnels are emptied by disposing the filter papers and wet earth materials in a trash bin. The measuring cylinders, funnels, and flasks are rinsed and returned on to the laboratory trolley. Assignment to be completed and submitted
From the theoretical data given in Table 1 below, calculate the permeability rate (ml/min), which is the volume of water drained (ml) divided by the percolation time (min), for each Earth material and enter results in the last column.
Draw an Excel bar graph, showing the permeability (ml/min) of the three samples (Fine Sand, Top Soil, and Gravel), and paste, or attach to the document.
Table 1. Permeability rate of different earth materials (theoretical data)
Sample #
(Sample name)
Sample Weight
(g)
Volume of water added
(ml)
Volume of water drained (ml)
Percolation time (min)
permeability rate (ml/min)
Fine Sand
25
100
80
7
Topsoil
25
100
55
15
Gravel
25
100
85
5
Discussion
Compare and discuss the permeability of the three earth-materials (Fine sand, topsoil, gravel) and give possible explanations for the differences among samples, with respect to the factors or physical properties which influence permeability. __________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
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