![density of salt water density of salt water](http://www.wikihow.com/images/9/98/Find-the-Density-of-Water-Step-10.jpg)
I usually rushed and did an imperfect job during the demonstration so they could "figure things out" but had the general idea of how to do it. You could also do this as a whole class to model what the process of writing a procedure "looks like" and then have them write their own later in the year. Especially since I did it early in the year, I wanted them to practice writing their own procedures and then critically analyzing what could be improved to make the procedure understandable for someone else. I usually demonstrate the procedure for students and then have them write a procedure and/or draw pictures of each step. Optional: Electronic Scale or Triple Beam Balance for extension Test tube rack Test tube drying rack Test tube brush (for cleaning) These optional ones are more about teaching them about these pieces of laboratory equipment.
![density of salt water density of salt water](https://i.pinimg.com/originals/b7/f6/87/b7f687907b9a072d962e661a83618786.jpg)
You just need to know that you're adding a relatively standard amount more for each additional color. Any kind of spoon that you use could be substituted for measuring spoons. Useful (but could substitute): 250mL beakers (4-6 of these) Food coloring Salt (about 36g = 6 Tablespoons) Stirring rod Measuring spoons Test tube Substitutions: Cups or bowls instead of beakers Natural dyes instead of food coloring (Think beets for pink etc.) Sugar instead of salt (This is a little messier and if not well cleaned up more likely to be a problem but works just as well.) Spoons instead of stirring rods. Example: About $25 for 400) You could substitute syringes, turkey basters, or some other device that would allow you to add the liquid to the bottom of a tube but pipets are so useful you might as well buy some if you don't have them. Required: Pipets (Can be purchased online from all kinds of vendors. I usually included every skill they could possibly practice. Students had measured and timed things for the velocity unit, but I was still teaching measurement and introducing them to the lab. You can make this experiment anything you like.