Why Does Water Float Lab Report

How Salty Does water have to be for the egg to float?
Materials and Equipment * Bag of clear 16-oz. plastic cups * Table salt * Water * Measuring cup, liquid * Container, 1-quart (qt.) * Spoon for stirring * Eggs (5)
Procedures
1. Take one egg out of the refrigerator and allow it to warm to room temperature. 2. Make a stock solution of 1 cup of salt dissolved in 1 qt. of water, as follows: a. Pour 3 cups of water into your 1-quart container. b. Add 1 cup of salt. c. Stir to dissolve. d. Add more water to make 1 qt. e. Stir to mix completely. 3. Make a two-fold serial dilution of the stock solution, as follows: f. Label four of the plastic cups 1–4. Label…show more content…
Measure out 3/4 cup stock solution, and add it to cup 2. Mix. j. Measure out 3/4 cup of the solution from cup 2 and add it to cup 3. Mix. k. Measure out 3/4 cup of the solution from cup 3 and add it to cup 4. Mix. l. What are the relative salt concentrations of cups 1–4? Example: Cup 2 is made up of half stock solution and half tap water, which is a 50 percent relative salt concentration. m. What are the absolute salt concentrations of cups 1–4? (If you want to convert to metric units, 1 cup of salt is about 292 g, and 1 qt. of water is 0.946 liters [L].) Write these concentrations down in your lab notebook. 4. Now, starting with cup 5 and working your way up, test the egg in each solution to see if it will float. Use a soup spoon to lift the egg in and out of the cups. 5. In which cup did the egg first float? (Save this solution for step 7.) If the egg floated in more than one cup, did you notice any difference in how it floated? 6. Now you know, within a factor of 2, how much salt it takes to float an egg. How can you narrow down the range further to get a more precise estimate? By doing another serial dilution, of…show more content…
Figure out a new serial dilution with smaller steps. For example, you could try diluting the solution by 20 percent with each step. That means with each step, the new concentration should be 80 percent of the original concentration. o. What amounts of stock solution and water do you need to use? (Remember that you will need enough solution to more than cover the egg.) p. Write up your new dilution procedure in your lab notebook, including the calculated salt concentrations for each cup. q. Make the new dilution series. Remember to start with salt concentration where the egg first floated. (If you don't have enough solution from the original serial dilution, make some more by starting from the stock solution.) 8. As before, test the egg in each cup, starting with the lowest salt concentration. In which cup did the egg float first? 9. If you want, make another dilution series, with even smaller steps, to improve the precision of your estimate. 10. Repeat the entire procedure with the four other eggs. Plot the densities for all five eggs on a chart. How much variation in density is there from egg to egg?

Background Research- How Salty Does the Sea Have to Be for an Egg to Float?
Density is the mass of a material per volume: ρ = | m
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