PHSC 101 Bowie State University Earth Science Lab Report

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
1. 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.
2. 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)
Fine Sand
Topsoil
25
25
50
50
42
30
3.45
10.00
Gravel
25
50
44
2.80
permeability
rate
(ml/min)
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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