### Present Remotely

Send the link below via email or IM

• Invited audience members will follow you as you navigate and present
• People invited to a presentation do not need a Prezi account
• This link expires 10 minutes after you close the presentation

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

# Water Density Lab Report

No description
by

## Meredith Demaree

on 3 October 2012

Report abuse

#### Transcript of Water Density Lab Report

Water Density Lab Report Introduction: Introduction:(Background information)

Water is the most abundant compound on the Earth, and covers about 70% of the Earth's surface. What is Density? Density of water is the weight of the water per its unit volume. Some things that effect the density of water are temperature, and salinity. What is Salinity? Salinity in water is the amount of salt in the water. Density effects and influences ocean currents. According to an article,
"Dense cold water can sink to the ocean floor causing deep ocean currents. All currents effect the climate; therefore the ocean effects the climate" (citation #2). Deep ocean currents are like underwater conveyer belts, that move swiftly throughout the oceans. It is known as the global conveyer belt. Water movements driven by differences in density are also known as thermohaline circulation because water density depends on its temperature (thermo) and salinity (haline).

Procedure:

To start off, you need three different cups, preferably shorter ones. You measure out 150ML of regular sink water in a beaker, then pour it into one of the cups. You repeat that step and pour the same amount of water into a second cup. Then, you take two different colors of food coloring, like yellow and blue, and put about 5 drops of one color into one of the cups, and 5 drops of the other color into the other cup. Then, chose one of the cups (blue) and add 7.4ML of salt into it, and mix together. Once it's mixed well, pour it into the empty cup. Analysis:
The equation used to get the percentages of salt in the water was:
ML Salt x
--------- = --------
150ML 100
This equation was used for each and every trial of the experiment. For Trial #1 the percentage of salt in the water was 4.93%, and the water layered, Yellow over Blue. For Trial #2 the percentage was 3.26% and the water layered again. We continued using the equation and changing the amount of salt in the water until we eventually got down to .413% salt in the water, and it still layered. The less amount of salt in the water, the less distinctly the colors were layered. Data Table & Graphs

Trial #1:
150ML of water mixed with 7.4ML of salt, or 4.93% slalt (Blue water)
150ML of freshwater (Yellow water)
-Trial #1 worked, and the waters layered. yellow/blue
Trial #2:
150ML of water mixed with 4.9ML of salt, or 3.26% salt (Blue water)
150ML of freshwater (Yellow water)
-Trial #2 worked, and the waters were layered yellow over blue, but just not as distinctly different.
Trial #3:
150ML of water mixed with 2.46ML of salt, or 1.64% salt (Blue water)
150ML of freshwater (Yellow water)
-Trial #3 worked, and the waters layered yellow over blue, but the yellow became more green. The Problem we are Testing:

What is the percent % difference of
salt in the water that will make the water
be in layers? Hypothesis:

If the percentage % of salt in the water (salinity) is more than the amount of regular water, then the salt water will be heavier and sink to make the bottom layer of the two. The freshwater would stay on top of the salt water, because it is less dense. Materials:

-Salt
-Measurement beaker
-Measuring spoons (ML)
-2 plastic cups
-2 different food colors (preferably 2 very distinct colors)
-spoons to mix the water
-plastic wrap (bigger than the cups' circumference)
-scissors Works Cited:

"Density of Ocean Water." Windows to the Universe. Ed. Jennifer Bergman. N.p., n.d. Web. 02 Oct. 2012.

http://www.csr.utexas.edu/grace/education/activities/pdf/DensityMatters.pdf

"How Ocean Currents Work." HowStuffWorks. N.p., n.d. Web. 02 Oct. 2012. <http://science.howstuffworks.com/environmental/earth/oceanography/ocean-current3.htm>. Then take a piece of plastic wrap and place it into the cup, to where it's touching the water, but still on the edges of the cup. While someone is holding the cup, another slowly pours the freshwater, in this case the yellow water, into the cup to where the plastic wrap is dividing the two waters. Then, ever so slowly, you pull the plastic out of the cup. If the experiment was performed correctly, the waters would have been divided, the yellow water on top and the blue water on bottom. Conclusion:
Hypothesis: If the percentage of salt in water (Salinity) is more than the amount of regular water, then the salt water will be heavier to make the bottom layer of the two. The freshwater would stay on top of the salt water, because it is less dense. The Hypothesis statement was correct, and it is concluded that water must have at least .413% salt (salinity) in the water to create layers. Because we did not have the time to keep going down on percentage of salt, we are unsure about the smallest amount of salt you can have for the water to still make layers. Next time, we know to work more diligently, and as a Team, instead of only two people doing the experiment. If we were to do future experiments, we would test to see if we could find out the lowest amount of salt the water can have, and still have the water in different layers. Trial #4:
150ML of water mixed with 1.23ML of salt, or .82% salt (Blue Water)
150ML of freshwater (Yellow water)
-Trial #4 worked, and the waters layered with a greenish-yellow on top, mixed in the middle, and blue on the bottom.
Trial #5:
150ML of water mixed with 0.62ML of salt, or .413% salt (Blue water)
150ML of freshwater (Yellow water)
-Trial #5 worked, and the waters layered green over blue.
Full transcript