Tuesday, March 14, 2017

Water Lab

Station 1 - What Water Can We Drink?

What are we testing?
- bacteria
- lead
- pesticides
- total nitrite
- pH

Materials:
- 5 dixie cups
- 5 little test tubes
- tap water in each dixie cup (amount isn't listed)

Procedures:
- Add tap water to each dixie cup
- Add 5 droplets of tap water from each cup into a separate test tube for each one
- Testing the pH using the test tubes, which will be looked at on Thursday

There are 5 little cups filled with tap water. Each of the cups are labeled as either pesticides, lead, bacteria, nitrite, and pH. A stick that will test this tap water will tell us whether or not the listed chemical(s) are inside of the tap water or not. 

Listed from left to right: pH, Nitrite, Bacteria, Lead, and Pesticides




Where does our tap water come from?
- rivers
- sewer
- ponds
- ground
2% potable (fresh, drinkable)

How is it filtered?
1.) it is extracted from the ground
2.) sent to a filtration plant to filter out the "bad"
3.) adds minerals to the water 

What is Chlorine?
- a toxic, irritant, pale green gas
- kills bacteria and microbiological organism 

Chlorine is very harmful because it is toxic and if it is combined with other chemicals, it will react easily. 

Lead
- NEVER safe
- lead piping
- soft or corrosive (easily tarnished)

Lead is very harmful to humans because it can cause air pollution, it moves through the ecosystem, and it can cause organ damage.  


Station 2 - pH of Ocean Water

Vocabulary:
acid: a molecule or other entity that can donate a proton or accept an electron pair in reactions
base: molecule that accepts protons
proton: a particle found in the nucleus with a positive charge 

What is pH?
--> acidity or alkalinity of a solution
- normal range for ocean water is 8.0-8.4
- pH levels fluctuate 
- lower numbers are acidic
- higher are alkaline
- 7 is about neutral

Materials:
- pH strips
- sample of ocean water
- cups
- color chart

Procedure:
- collect sample
- dip test strip into the ocean water

Why does the strip change color?

Acids and bases aeither accept or donate a hydrogen ion and the color changes depending on whether or not a hydrogen ion has been accepted/denied

How does this relate to the environment?

The release of carbon dioxide and other greenhouse gases in the environment increase the pH in the ocean. Oceans absorb CO2 and turns it into carbonic acid, leading to higher acidity. This limits shell growth in marine animals and damages reproductive disorders in fish. The ocean's pH has been 8.2 for the past 300 million years, but it is now 8.1 which can show how these gasses and chemicals affect our environment. 





Station 3 - Bacteria in a Pond?

What are we testing?
Whether or not there is bacteria in a pond

Materials:
- 5 dixie cups
- small test tubes that include the pond water 

Vocabulary:
microscopic: anything that is alive and is able to be seen without a microscope (usually the bigger things)
photoautotroph: anything that produces its own food through photosynthesis
heterotroph: an organism deriving its nutritional requirements from complex organic substances

Finding bacteria in a pond is significant to our community because ponds are stagnant, so all of the water stays still. That means all of the waste that is building up in the pond will stay there. If humans or other living things are exposed to the bacteria in the ponds, it will be harmful to people's immune systems. It is hard for biotic factors to process bacteria that shouldn't be there in the first place. 



Results

  • Tap
    • Bacteria = Negative (no bacteria was detected)
    • pH = 6.5
    • Chlorine = 0
    • Total hardness = 250
    • Total nitrate = 1.0
    • Nitrite = 0.75
    • Pesticide = Invalid
    • Lead = Invalid
  • Pond
    • Bacteria = Negative (no bacteria was detected)
    • pH = 6.0
    • Chlorine = 0
    • Total hardness = 0
    • Total nitrate = 2.0
    • Nitrite = 1.5
    • Pesticide = Invalid
    • Lead = Invalid
  • Ocean
    • Bacteria = Negative (no bacteria was detected)
    • pH = 7.5
    • Chlorine = Invalid 
    • Total hardness = Invalid
    • Total nitrate = 0
    • Nitrite = 0
    • Pesticide = Invalid
    • Lead = Invalid

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