Egg Flotation Outline

Experimental Procedure

1. Take five eggs out of the refrigerator, use a permanent marker to label them 1-5, and allow them to warm to room temperature.

2. Make a stock solution of 1 cup of salt dissolved in 5 cups of water, as follows:

a. Pour 3 cups of water into your large container.

b. Add 1 cup of salt.

c. Stir to dissolve some of the salt. It will not all dissolve yet.

d. Add 2 more cups of water.

e. Stir to dissolve the rest of the salt. The salt should be completely dissolved before you go on to the next step.

i. This may take several (5 to 10) minutes of stirring, so you may need to be patient.

3. Make a two-fold serial dilution of the stock solution, as follows:

a. Label five of the plastic cups 1-5. Cup 1 will be for the stock solution, cups 2-4 will be for the dilutions, and cup 5 will be plain tap water.

b. Add 3/4 cup of your stock salt solution to cup 1.

c. Add 3/4 cup plain tap water to cups 2-5.

d. Measure out 3/4 cup stock solution, and add it to cup 2. Mix.

e. Measure out 3/4 cup of the solution from cup 2 and add it to cup 3. Mix.

f. Measure out 3/4 cup of the solution from cup 3 and add it to cup 4. Mix.

g. 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.

h. 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 grams [g], and 1 cup of water is 237 milliliters [mL].) Write these concentrations down in your lab notebook.

4. Now, starting with cup 5 and working your way up, test an 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...