This lab has been designed to help students understand and feel comfortable with the density of liquids. The liquids you will need for this lab are: alcohol, tap water, salt water. I make the salt water myself and super-saturate it by heating the water and slowly adding more and more salt. If the salt water is not saturated, they will not see a huge difference in the density and it will be harder to distinguish between the liquids. Also, to save resources, I typically have they pour the liquids back into the original containers (put them in different places around the room to ensure they don't get confused and contaminate the bottles). Students will be expected to graph their data and answer many analysis questions at the end to synthesize the information.