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

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.

$4.$Make 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 $\frac{3}{4}$ 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 $\frac{3}{4}$ cup of the solution from Cup $3$ and add it to Cup $4.$ Mix.

g$.$ What are the absolute mass concentrations of salt in cups $1-4?($T$$ calculate with metric units use these conversions: $1$ cup of salt is $292.$ grams $[$g$],1$ cup of water is $237$ milliliters $[mL],$ and $\frac{3}{4}$ cup of stock solution is $177\mathrm{.}75$ milliliters $($mL$).$ Write these concentrations down in your lab notebook Review the introduction links to an extemal site, section if you need help with your calculations.

h$.$ What are the relative salt concentrations in cups $2-4$ compared to the original stock solution? Use the absolute mass concentrations that you calculated in the previous step for your calculations. Example: Let's assume that the original stock solution in Cup $1$ has a salt concentration of $500.$ G$/$L Cup $3$ has a salt concentration of $125$ g$/$L The relative salt concentration of $25\%$ compared to cup $1.$

$5.$ Now, starting with cup $5$ and working your way up$,$ test an egg in each solution to see if it will float.

$6.$ In which cup did the egg first float if the egg floated in more than one cup, did you notice any difference in your notebook, including the egg's number.