Download Weathering Lab Data Sheet

ESS
Name _________________________ Period __________
MECHANICAL WEATHERING
Part 1 Prediction: _______________________________________________________
_______________________________________________________________________
Data Table 1 Weathering of Different Size Marble Chips
Weathering time
Mass of marble chips (g)
Observations:
(min.)
Large
small
Size, shape, water color
0
3
6
9
12
15
total mass lost
(Line) Graph 1
Mass of Large and Small Marble Chips vs. Time
20.0
Mass of Chips (g)
19.5
19.0
18.5
18.0
17.5
17.0
0
3
6
9
12
15
Time (min.)
Part 1 Questions
1. What is the effect of TIME on the weathering of the rocks?
1. What was the PERCENT change in mass of the LARGE marble chips compared to the SMALL chips?
Loss in mass x 100
Original mass
loss in mass x 100
original mass
2. How does the amount of surface area exposed contribute to weathering (pg. 262)
3. What do you think would happen if you continued shaking the marble chips for 24 hours or longer?
Name _________________________ Period __________
Mass of chips (g)
Amount of weathering
ESS
time
Small
large
Particle size
Summarize your results by restating your hypothesis and using your data.
ESS
Name _________________________ Period __________
Part 2 Prediction:_____________________________________________________________
____________________________________________________________________________
Data Table 2
Change in Mass of Rocks with Different Composition/Hardness
Hardness on
Initial
Final
Mohs scale
Mass (g)
Mass (g)
Observations
Rock Type
Sandstone
(quartz)
Halite
(rock salt)
(Bar) Graph 2
Change in Mass vs. Rock Type
25 g
20 g
15 g
10 g
5g
0g
Initial
Final
Sandstone Rock
Initial
Final
Halite
Part 2 Questions
4. How did the change in mass of the sandstone compare to the change in mass of the halite?
5. Sandstone is composed of the mineral quartz, use the table on page 701 in your text to find the
hardness of the two minerals
6. Explain the relationship between the hardness and the amount of abrasion, as observed in the
activity?
7. What conclusions can you draw between the results obtained in this activity and the natural process of
weathering that takes place in nature?
Name _________________________ Period __________
Amount of abrasion
ESS
1
10
Hardness
Summarize your results by restating your hypothesis and using your mass data.
ESS
Name _________________________ Period __________
CHEMICAL WEATHERING
Part 3 Prediction: _________________________________________________________________
________________________________________________________________________________
Data Table 3 Chemical Weathering of Rocks with Different Composition
Time
Observations / Descriptions
Limestone
Granite
Chalk
Composition
(minerals)
At the start
20 minutes later
Part 3 Questions
8. What changes did you observe in each sample?
9. What evidence(s) did you observe to support the idea that a chemical change occurred?
10. How is the composition of granite (page 118) different from the minerals in limestone or chalk
(page 107)?
11. Describe how acid rain forms (acid rain)
Name _________________________ Period __________
Chemical weathering
Chemical weathering
ESS
Amount of calcite
Amount of quartz
Summarize your results by restating your hypothesis and using your data.
ESS
Name _________________________ Period __________
Part 4 Prediction: ________________________________________________________________
________________________________________________________________________________
````````
Data Table 4
3
Chemical Weathering of Pyrite and Granite
Time
Observations
Pyrite Chips
Water/Acid Solution
clear
Granite Chips
Water/acid Solution
Before
Days later
(after)
Before
clear
Days later
(after)
Part 4 Questions (use pg. 261 in text)
12. What changes did you observe that would indicate that chemical weathering took place?
What is the chemical formula for pyrite? What substance in pyrite caused the chemical change?
13. Label the substances and BALANCE the chemical equation for the oxidation of iron:
Fe
_______
+
O2
________
Fe2O3
____________
14. Label the substance in the chemical equation for forming carbonic acid (acid rain)
H2 O
___________
+
CO2
_____________
H2CO3
______________
15. How does HYDROLYSIS contribute to the chemical weathering of rocks? (pg 260)
Name _________________________ Period __________
Chemical weathering: oxidation
ESS
Amount of iron
Summarize your results by restating your hypothesis and using your data.
ESS
Name _________________________ Period __________
During/After the class post-lab discussion on the results of the weathering lab, Answer the analysis questions
below IN COMPLETE SENTENCES
1. In Part 1, what is the effect of TIME on the amount of weathering? Give an example using
the rocks.
2. In Part 1, how did the MASS of the rocks/minerals change over TIME? Give an example
using the rocks.
3. Based on the percent data in Part 1, how did different PARTICLE SIZE of rocks affect the
weathering?
4. From Part 2, explain the relationship between hardness of the minerals in the rock and the
amount of abrasion that occurs. Give an example using two rocks with different hardness.
5. Which of the different rock/mineral samples in Part 2 (sandstone or halite) had the LEAST
change of mass? Use the composition of the minerals to explain.
ESS
Name _________________________ Period __________
6. Describe what would happen if you continued to shake/weather the rocks in water
for 24 hours or longer?
7. From Part 3, which rocks were weathered by the weak acid (rain)? What are they
composed of?
Why is granite resistant to chemical weathering in acid?
8. From Part 4, What evidence did you observe to support the idea that a chemical
change occurred when pyrite was chemically weathered ?
What mineral in pyrite caused it to chemically weather?
9. What is the difference between mechanical weathering and chemical weathering of rock?
ESS
Name _________________________ Period __________
weathering
Mass of chips (g)
Part 1
Particle size
time
Degree of abrasion
Rounding of fragments
Part 2
1
10
Hardness on Mohs scale
Time in river/stream
Amount of CALCITE
In the rock
Chemical weathering
oxidation
Chemical weathering
Chemical weathering
weathering
Parts 3 and 4
Amount of QUARTZ
in the rock
Amount of IRON
in the rock
ESS
Name _________________________ Period __________
1. What type of weathering is in Washington D.C. if AYT is 23°C and AYP is 104 cm?
__________________________________________________________________
2. If AYT in D.C. dropped 26°C but the AYP stayed the same, what kind of weathering
would dominant? _______________________________________________
3. Phoenix, AZ. Has an AYT of 20°C and an AYP of 20 cm. How would the climate in
Phoenix have to change for moderate chemical weathering to become dominant?
_________________________________________________________________
4. According to the graph, no frost action occurs at a AYT above 13°C. Why?
____________________________________________________________________
5. In general, how does a climate with strong chemical weathering differ from a climate
with strong mechanical weathering?
______________________________________________________________________
ESS
Name _________________________ Period __________