science labs 2 – exclusivewritings.com

i will upload the work as a pdf when you decide to accept the work

there is a total of 5 labs to compelte

Build a Water Treatment System

HYPERLINK “http://www.searchquotes.com/quotation/Water_is_life%27s_mater_and_matrix%2C_mother_and_medium._There_is_no_life_without_water./32287/” Water is life’s mater and matrix, mother and medium. There is no life without water.
~HYPERLINK “http://www.searchquotes.com/quotes/author/Albert_Szent-Gyorgyi/”
Albert Szent-Gyorgyi

There are five steps to basic water purification: aeration, coagulation, sedimentation, filtration, and disinfection. Our project will take us through the first four.
Aeration adds air to the water. It allows gases trapped in the water to escape and adds oxygen to the water.
Coagulation is the process which allows dirt and other suspended solid particles to chemically ‘stick together’? into floc (clumps of alum and sediment). During this step, the water is also clarified, or made clear and colorless.

Sedimentation is the process that occurs when gravity pulls the particles of floc to the bottom of the container. So as the water sits undisturbed, most of the floc settles, preparing the water for the next step.

Filtration is the process where remaining solid particles and floc are separated and removed from the water.

Disinfection is the final step, in which water is chemically treated to remove bacteria and other micro-organisms. These unseen bacteria can cause severe sickness and even death in humans.

Objectives: Learn the different steps of water treatment and construct a mini water treatment system yourself

Requirements:

1/2 L of swamp water (or tap water with mud or dirt added)

2 L soda pop bottle with its lid

2 L plastic soda pop bottle—cut in half (be careful with cutting)

A container for water

2 cups of 20 oz each

1 tbsp HYPERLINK “http://www.hometrainingtools.com/alum-100-g/p/CH-ALUM/” alum (aluminum potassium sulfate) – Alum is found in grocery store in baking section

2 cup HYPERLINK “http://www.hometrainingtools.com/sand-fine-white-1-lb/p/GS-SANDFIN/” fine sand

1 cup HYPERLINK “http://www.hometrainingtools.com/sand-coarse-1-lb/p/GS-SANDCRS/” coarse sand

1 cupHYPERLINK “http://www.hometrainingtools.com/pebbles-fine-gravel-1-lb/p/GS-PEBBLE/” small pebbles

1 HYPERLINK “http://www.hometrainingtools.com/filter-paper-11-cm–10-pkg/p/CE-FILTPAP/” filter paper or coffee filter

1 HYPERLINK “http://www.hometrainingtools.com/rubber-bands-bag/p/GS-RUBBAND/” rubber band

1 large spoon for stirring

HYPERLINK “http://www.hometrainingtools.com/spatula-stainless-steel/p/CE-SPATULA/” Spoon for scooping the alum

HYPERLINK “http://www.hometrainingtools.com/stop-watch-digital-2-case/p/ME-STOPWAT/” Stopwatch or timer

CAUTION: Because we won’t disinfect our water, it is NOT safe to drink.

Procedure

1. Pour swamp water /tap water mixed wth dirt in the 2-liter bottle with a lid. Notice how it looks and smells.

2. Put the lid on the bottle and shake vigorously for 30 seconds. Then pour the water back and forth between the two cups about 10 times.

3. Pour the water into the bottle with its top cut off. Again notice how the water looks and smells.

4. Add 2 tablespoons of alum to the water in the bottle with the top cut off. Use the spoon to slowly stir the water for five minutes. What do you notice about the water as you stir it? Record that in observations.

5. Now let the water sit undisturbed for 20 minutes, checking it every five minutes to note how it looks and smells (without moving it).

6. Use a rubber band to secure the filter paper to the mouth of the bottle with its bottom cut off. Put it upside down in the beaker.

7. Pour the pebbles into the bottle. Then pour the coarse sand on top of the pebbles and the fine sand on top of the coarse sand.

8. Carefully pour about two liters of clean tap water through, being careful not to disturb the top layer of sand.

9. Pour the top 2/3 of the swamp water through the filter, taking care to leave the sediment in the swamp water bottle.

10. Once all the water has passed through the filter, compare the swamp water to the filtered water. How do they look and smell different?

11. Remember: You CANNOT drink your filtered water because it is not disinfected.

12. Write a detailed lab report of your experiment. Guidelines for writing the lab report are given in lab. 2.

Air Quality Investigation

There’s so much pollution in the air now that if it weren’t for our lungs there’d be no place to put it all. ~ Robert Orben

The atmosphere is a complex natural gaseous system that is essential to support life on planet HYPERLINK “http://en.wikipedia.org/wiki/Earth” o “Earth” Earth. Air pollution is the introduction of HYPERLINK “http://en.wikipedia.org/wiki/Particulates” o “Particulates” particulates, HYPERLINK “http://en.wikipedia.org/wiki/Biomolecule” o “Biomolecule” biological molecules, or other harmful materials into the HYPERLINK “http://en.wikipedia.org/wiki/Earth%27s_atmosphere” o “Earth’s atmosphere” Earth’s atmosphere, causing disease, death to humans, damage to other living organisms such as food crops, or the HYPERLINK “http://en.wikipedia.org/wiki/Natural_environment” o “Natural environment” natural or HYPERLINK “http://en.wikipedia.org/wiki/Built_environment” o “Built environment” built environment. Air pollution may come from HYPERLINK “http://en.wikipedia.org/wiki/Anthropogenic” o “Anthropogenic” anthropogenic or natural sources. Air pollution has been recognized as a threat to human health as well as to the Earth’s HYPERLINK “http://en.wikipedia.org/wiki/Ecosystems” o “Ecosystems” ecosystems.

Objectives:To conduct an experiment to sample and measure the particulate matter in the air at various locations and/or elevations in your neighborhood
To discuss why different locations would have different amounts of particulate matter and how this would affect animal or plant life in the area.

Materials:
3 x 5 index cards
Magnifying glass
Clear packing tape
Rulers
5 mm grid paper (this can be printed off the internet or is available at any stationery store
Calculators
Masking tape

Procedure:
1. Begin by cutting a 3cm x 5cm rectangle out of the center of your index card.
2. Place clear packing tape on one side of the card so the sticky part is exposed through the hole.
3. Choose 3 locations for your collection cards that will not get a lot of human interference for a minimum of a 24-hour period.
4. Write your names and the location where you will be placing the card on the back of the card.
5. Once you have chosen the location you will be placing the card or slide, decide how you will attach your card to this location (tape, string or clothespins).
6. Attach the cards to the three locations you have chosen in the neighborhood.
7. After a minimum of 24 hours return to your cards and take them down.
8. Place your 5 mm grid paper on the non-sticky side of the card so that it shows through the packing tape.
9. Using the magnifying glass, count and calculate the number of particulates in each 5 mm grid for a total area of 3cm².
10. Be sure to record all of your collection information in your lab report.

11. Write a detailed lab report of your experiment. Guidelines for writing the lab report are given in lab. 2.

Comparing Vinegar with a Chemical Based Supermarket Cleaner

Great things are done by a series of small things brought together.

~ Vincent Van Gogh

As wonderful as technology has been in enhancing our lives and creating longevity, it’s also been a double-edged sword. Human activity and the constant drive to expand has come at the expense of the global environment. Greenhouse gases are contributing to global climate warming as emissions caused by human activity continue to increase. The depletion of the ozone layer, essentially the protector of life on earth, has never been greater. Chemical agents sprayed into the atmosphere rise-upward and take their toll on the ozone and our environment. Empty containers often end up in landfills indefinitely. We need to do our part and take action now through use of natural and biodegradable products.

Materials required:

  • Diluted vinegar (half vinegar with half water)
  • Supermarket cleaning product that is safe on glass (such as Windex)
  • Cleaning cloth
  • Old newspaper

Procedure:

1. Find a dirty window (glass pane). It should be a surface that is visibly dirty all-around.

2. Scrunch up your newspaper and pour some vinegar on it. The paper should be saturated, but only so it’s partially wet with vinegar (enough to clean the surface). Scrub one-half of the window/mirror for about a minute, making sure to scrub in a swooping circular motion.

3. On the second-half of the window, spray your supermarket cleaning agent. Take your cleaning cloth and clean the second-half of the window for a minute, using the same swooping circular hand motion.

4. When you’re done, observe the window / mirror. Which half is cleaner? Is there a noticeable difference?

Answer the following questions:

1. Which method of cleaning the window do you think is the most environmentally friendly?

2. Was there enough of a different between the chemical cleaning agent and the vinegar to justify its use and its potential negative effects on the environment?

Note

With an eye on the environment (and the consumer pocket-book), many big-name companies are starting to jump on the “natural” bandwagon. You’ll find more natural-based cleaners these days than in the past, but be weary of labels! Some companies use clever marketing gimmicks to make their products appear to be “natural”, when in fact they are not. A common ploy is to label a bottle with “natural orange/lemon scent”. When a consumer glances at the product they see “natural” and assume the cleaner is natural. Always check the listed ingredients to see if the product you’re purchasing is truly made of natural ingredients.

Many supermarket cleaners contain harsh chemicals that are dangerous to the environment and atmosphere. Vinegar is a non-toxic acidic liquid that can clean just as effectively as many chemical based agents, without the damaging side-effects. The newspaper was used to demonstrate how recycled material can make a viable substitute for cleaning clothes, which requires a lot of energy to produce.

Changes in Sea Level

But we have only begun to love the earth. We have only begun to imagine the fullness of life.
How could we tire of hope?–so much is in bud.

~ Denise Levertov

Sea level continually changes in response to numerous factors, including glacial melting, tectonic forces, and climatic changes. Currently, sea level is rising at a rate of 1.5 to 3.9 mm/year. Studies by the U.S. Environmental Protection Agency and other organizations indicate that global warming may be linked to increases in sea level. Global warming is a worldwide rise in surface temperatures. Scientists hypothesize that global warming is caused by human activities, such as the burning of fossil fuels. Even a small rise in global temperatures can melt glaciers and make seawater expand, both of which increase the volume of water in the oceans.

In this lab we will be analyzing how have coastlines and sea level changed during geologic time?

Our major objectives for the lab would be:

• Observe and measure changes in coastlines.

• Describe changes in sea level over geologic time.

• Predict the impact of rising sea level on coastal regions.


Materials needed
Metric rulers
String

Procedure

1. Take a few minutes to study the sea-level map on the next page. Note the map scale. You will use the map and the map scale to answer the questions in this lab.

2. Use the string to measure distances along the coast or between two points that are not in a straight line. For example, you can lay the string along the coast so that it follows the outline of the coast, then measure the distance by laying the string along a ruler.

Answer the questions that follow:

1. How does the landward limit of the coastline 5 million years ago compare to its current location? How does it compare to the location of the coastline 20 000 years ago?

2. Locate South Carolina on the map. How far did its coastline extend into the Atlantic Ocean 20 000 years ago? How far inland was its coastline 5 million years ago?

3. Measure and record the entire length of the current coastline and its length 20 000 years ago. Describe how it has changed. What caused these changes?

4. Use the map to describe how sea level has changed in the last 20,000 years. Why do you think these changes occurred?

Additional questions

1. The last ice age peaked roughly 10 000 years ago. Since then, sea level has risen approximately 130 m. Describe the effect of small rises in sea level on coastal areas.

2. The mass of huge glaciers exerts pressure on underlying land and causes it to sink. When these glaciers retreat, the land that they covered often rises, or rebounds. Where on the map would you expect glacial rebound to be occurring? How might this rebound affect the levels of seas and other large bodies of water?

3. Global sea level could rise by 30 cm within the next 70 years. Predict which areas on the map would be affected most. Explain your answer.

4. Discuss the potential impacts of rising sea level on low-lying coastal areas.

Acid Rain and Counteracting its Detrimental Effects

In the end, we will conserve only what we love. We will love only what we understand. We will understand only what we are taught.

~ Baba Dioum

Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). Aqueous solutions are termed to be acidic if the pH is less than 7.00 and caustic (alkaline) if the pH is greater than 7.00. A pH of 7.00 is neither acidic nor caustic.Each pH unit change represents a 10 times change in the acidic/caustic character of the solution. Universal pH paper is commonly used to determine the pH of a number of aqueous solutions.

pH of some common solutions

Acid rain can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by anthropogenic emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results. The chemicals in acid rain can cause paint to peel, corrosion of steel structures such as bridges, and erosion of stone statues. The lower pH concentrations in surface water that occur as a result of acid rain can cause damage to fish and other aquatic animals. At pHs lower than 5 most fish eggs will not hatch and lower pHs can kill adult fish. As lakes and rivers become more acidic, biodiversity is reduced. Acid rain has eliminated insect life and some fish species, including the brook trout in some lakes, streams, and creeks in geographically sensitive areas, such as the Adirondack Mountains of the United States. Soil biology and chemistry can be seriously damaged by acid rain. Some microbes are unable to tolerate changes to low pH and are killed. Other plants can also be damaged by acid rain, but the effect on food crops is minimized by the application of lime and fertilizers to replace lost nutrients. In cultivated areas, limestone may also be added to increase the ability of the soil to keep the pH stable, but this tactic is largely unusable in the case of wilderness lands. When calcium is leached from the needles of red spruce, these trees become less cold tolerant and exhibit winter injury and even death.

In this lab we will see how a simple acid in lemon juice (citric acid) can be somewhat neutralized by baking soda (sodium bicarbonate).

The reaction between baking soda and lemon juice is an acid-base reaction, because it involves an acid (citric acid in the lemon juice) reacting with a base (sodium bicarbonate, more commonly known as baking soda). We can write this reaction as follows:

C6H8O7 + 3NaHCO3 <—> Na3C6H5O7 + 3H2CO3

In words, a molecule of citric acid reacts with three molecules of sodium bicarbonate to form a molecule of sodium citrate and three molecules of carbonic acid. Although an acid is reacting with a base, this is not a neutralization reaction. In a neutralization reaction, the products are water and a salt; our products, however, are a weaker acid and an organic salt. If you were to measure the pH of a solution containing the products, it would be lower than 7 (acidic).

On the left side of the equation, citric acid is the acid and sodium bicarbonate is the base; on the right side, carbonic acid is the acid, and sodium citrate is the base. The forward reaction is favored because citric acid is a stronger acid than carbonic acid (or, alternately, because sodium bicarbonate is a stronger base than sodium citrate). However, the difference is not very significant, and hence it is indicated with the double-headed arrows that both the forward and reverse reactions will occur, leading to an equilibrium.

This is not the whole story, however. The carbonic acid formed in the above reaction dissociates rapidly to form carbon dioxide and water:

H2CO3(aq) —> CO2(g) + H2O(l)

When this happens, you will notice the solution bubbling and foaming rapidly.

Materials needed:

  • Lemon juice bottle from the grocery store
  • Baking soda
  • Measuring cups and spoons
  • Water
  • Spoon for stirring
  • Universal pH paper or pH testing strips (available at a hardware store or store that sells pool and aquarium supplies)
  • Eye Droppers or Glass droppers or Plastic droppers

Procedure

1. Measure 2 tablespoons of lemon juice. Transfer it to a large cup or container and dilute with 5 tablespoons of water rinsing any lemon juice from the spoon

2. Using universal pH paper measure the pH of the lemon juice solution.

3. Add 1 tablespoon of baking soda in another cup.

4. To the second cup with baking soda, add 5 tablespoons of water and stir with a spoon.

5. Using universal pH paper measure the pH of the baking soda solution.

6. Add one dropper full of the baking soda solution to the lemon juice solution, stir and note the pH.

7. Keep repeating until the pH is close to neutral. Remember it will still yield an acidic solution.

8. Measure how much of the baking soda solution remained in the beaker and calculate how much was used up.

9. Write a detailed lab report explaining your experiment and results. Use the template on how to write a lab report from your second lab.

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