Acid Rain Lab Report 501634

Title of Experiment INTRODUCTION In this experiment, we tested which building material would be the most resistant to acid rain for constructing a statue. The three variable materials are granite, limestone and marble. Acid rain is caused when fossil fuels such as sulfur dioxide and nitrogen oxides combines with moisture to create this precipitation with a pH of 5.5 or lower. This relates to real life because it is an erosion problem for many buildings depending on their constructive material.

PROBLEM What is the effect of the type of rock on the change in mass when exposed to vinegar in a period of time?

HYPOTHESIS If Granite is exposed to vinegar over time then the change in mass will be less than limestone and marble because it is resistant to the chemical weathering.

VARIABLES Independent Variable: Type of building material(Limestone, Granite, Marble) Dependent Variable: Change in mass of building materials(g) Constants:  Volume of Vinegar (100mL to each)  Starting Mass (50 grams +3 -3)  Time soaked  pH of Vinegar Control: Soaking all building materials in 100mL of distilled water for the same amount of time as the vinegar.

MATERIALS           

Limestone Marble Granite beakers(250mL) Graduated Cylinder Distilled Vinegar(100mL) pH indicator pH meter (digital) Distilled Water Digital Scale Paper Towels

SAFETY    

Don’t sniff materials Keep apron and goggles on at all time Dispose of materials correctly Add rock sample gently into beaker so it doesn’t break

PROCEDURE (copy and paste your approved procedure below) 1. Pre-soak all rock samples in distilled water for 24 hours.

2. Choose a sample of rock from the distilled water and pat it dry with paper towels. 3. Then place the rock sample on the zeroed digital scale. Add or remove rock samples until the total mass is 50g (+/- 3g). 4. Record the initial mass of the rock sample in Data Table 1. 5. Place the rock sample into a properly labeled (B4 Limestone Vinegar) 250mL beaker. 6. Using a graduated cylinder, measure out 100mL of vinegar and pour into the labeled beaker with the rock sample (replace vinegar with distilled water for control). 7. Pour a small sample of vinegar and a small sample of distilled water into two separate beakers (from their original samples). 8. Measure each solutions pH with a digital pH meter and with 5 drops of Universal indicator solution. (Use the color chart provided to determine the initial pH.) 9. Record the initial pH and initial pH color in Data Table 1. 10. Allow samples to soak for 4 days 11. Remove all rock sample from the beaker using a pair of tweezers and put them on a dry paper towel. 12. Pat rocks dry with new paper towel 13. Place all samples on a zeroed scale. 14. Record the final mass in Data Table 1 15. Repeat steps 8 & 9 using 10 drops of Universal Indicator solution Cleanup Procedure: 1. Return all rock samples to the correct beaker by the scales. 2. Discard of solution in the waste beaker in the hood. 3. Remove tape from beaker and throw away. 4. Wash and dry beaker and tweezers and return to lab cart. 5. Discard of paper towels in the trash bin 6. Wash hands with soap and water. 7. Return goggles to cabinet. 8. Stand at your lab table for safety check by teacher.

RESULTS Data Table 1:

Solution

Type of Material

Initial Mass (g)

Vinegar

Granite

51.9

51.9

0

2

2

yellow

yellow

Vinegar

Limestone

47.4

43.3

-4.1

2

5.4

yellow

bluegreen

Vinegar

Marble

50

46

-4

2

5

yellow

bluegreen

Distilled Water

Granite

52.5

52.5

0

7

6.7

bluegreen

bluegreen

7.1

bluegreen

blue

Distilled Water

Limestone

51.8

Final Mass (g)

51.9

Change in Initial Final Initial pH Final pH Mass (g) pH pH Color Color

0.1

7

Distilled Water

Marble

50.5

50.5

0

7

7

bluegreen

blue

Calculations Describe how the calculations were performed. For example, someone would describe the example below by saying: “the average of all trials was calculated by taking the sum of all trials and dividing by the number of trials (see calculation below)”. Then, provide the formula and one sample calculation.

For example: Formula: Trial 1 + Trial 2 + Trial 3 + …… = Total ÷ # of Trials = Average Calculation: 5+4+5+6 = 20 ÷ 4 = 5 (lbs) Graph 1:Average Weight for Pacific Salmon Species

SUMMARY x Summarize the main findings of the data. DO NOT EXPLAIN CONCLUSIONS HERE. Describe what the data are (using number values) and explain how the data looks in the graph as compared to the data table. Use actual numbers to your answer. Discuss each data point and compare them to the others. Does the way the graph looks the data collected and/or calculated? Explain why. Example Summary of “Atlantic Salmon” graph above: In the experiment, the average weight of the salmon species in the Pacific Ocean ranged from 5lbs to 15 lbs. The lightest salmon species was the humpback salmon, weighing 5lbs on average. The heaviest

salmon species was tied between the king salmon and the chum salmon at 15lbs on average. The silver salmon weighed 12 lbs average and the sockeye salmon weighed 8lbs on average. The graph clearly represents the data collected because the taller bars represent the heaviest average salmon while the shortest bars represent the lightest average salmon.

CONCLUSION The hypothesis of this experiment proposes that granite when exposed to vinegar over time, will change in mass the least compared to limestone and marble. The data does prove that granite changes the least in mass. When soaked in vinegar for 4 days, granite did not change at all and stayed at 51.9 grams, while the building material marble decreased 4 grams. The material that changed in mass the most was limestone. It decreased 4.1 grams, because limestone is the most porous out of the three building materials tested. Granite is the least porous material so the vinegar did not impact it as much. Granite is by far the best material to use for a statue because it does not get as affected from acid rain compared to limestone and marble.

VALIDITY Use the paragraph descriptions below to help you outline a clear evaluation of the data’s validity. Use the notes you jotted down after lab to help you brainstorm. Leave 1-2 spaces between each section (improvements and constants) for clearer formatting. Improvement with explanations: In one paragraph, identify one improvement that could be made to the experimental design (meaning the methods used in the procedure, not in regards to error in your actions during lab). What could be improved in the methods of measurement in order to make the data more valid? What additional materials or apparatus’ would be useful in making this data more valid? Questions you might ask of the example experiment are: were the salmon all measured hanging or flat on the table? Were they dried first? Did the salmon all eat shortly before being weighed? How many fish were used to calculate the average (number of trials)? These are the types of things you want to focus on improving, not on any human error. For example, the person measuring the fish does not make a difference because anyone should be able to perform the same measurement and produce the same results. Assume all materials (scales, thermometers, rulers, and glassware) are calibrated. Materials used are not constants, only what you DO with them. Don’t forget to explain how improving a design flaw would increase the validity of the data. For example, if left unchanged, what might it do to change the data collected? Would the mass/volume/temperature increase or decrease unnaturally and why? Constants with explanations: In a second paragraph, identify at least three (3) variables held constant in the experiment and explain how keeping each of these variables constant helped to increase the validity of the data (an explanation is required of each constant). To explain how the constants affect the data, answer this question: if allowed to change, what might that variable do to change the data collected? Would the mass/volume/temperature increase or decrease unnaturally and why?

ENVIRONMENTAL IMPACT Write a brief summary of the environmental impact of the process or product you tested. Explain what the impacts are and your answer with data (statistics, maps, or graphs) from an outside resource (cite all sources used). Are there alternatives to the use of this process or product? Give examples of how they are used or what their environmental impact may be. In summary, would you choose to use this product? Why or why not? Explain the pros and cons of implementing its use (cost is often a factor here).