Chemistry Project Ideas

Materials and Equipment

• salt
• pepper
• tea kettle
• 2 small glass jars with lids
• water
• measuring cup
• funnel
• coffee filter
• magnifying lens

Experimental Procedure

1. Before you begin, you will want to examine your salt and pepper closely and make some initial observations. Place some salt and pepper on a napkin and using your magnifying glass, make some observations and draw what you see. What do you notice? Record your observations in a data table like the one shown below:
   

   	Salt	Pepper
   Observations before mixing
   Amount before mixing
   Observations of mixture
   Total amount of mixture
   Observations after adding water
   Observations after separation & drying
   Amount after separation & drying

2. In your glass jar, add 1/4 cup of salt, and 1/4 cup of coarsely ground pepper.
3. Put the lid on your jar and shake until the salt and pepper are completely mixed together.
4. Using your magnifying lens, look closely at the mixture. What do you notice? Can you still see the individual grains of salt and pepper? Record your observations in your data table.
5. Put the teakettle on the stove, and heat up some boiling water.
6. Pour 1/2 cup of boiling water into your jar and stir with a spoon. Be careful and get help from a parent or adult, the glass will get very hot!
7. Using your magnifying lens, look closely at your solution. What do you notice? Can you still see the individual grains of salt and pepper? Record your observations in your data table.
8. Place the coffee filter in the funnel and place the funnel in the top of your second glass jar to make your separation apparatus:
   

9. Slowly pour the solution over your filter, being careful not to pour too much at once. As the solution seeps through the filter, let it collect in your jar.
10. Now look at the coffee filter, what do you see? Carefully scrape off any particles with a spoon and place them into the first glass jar.
11. Place both glass jars onto a cookie sheet, and bake in the oven at 325 degrees until all of the water has evaporated from both of the jars. You will need an adults help with this.
12. Remove the jars and allow them to cool to room temperature before handling. They will be very hot!
13. After the jars are cool, use your magnifying lens to make observations of the two jars. What do you notice? Can you still see the individual grains of salt and pepper? Are they mixed together or separated? Record your observations in your data table.
14. Now carefully use a measuring cup to measure the amount of salt and pepper you ended up with. Do these amounts match the amounts you started with? Why do you think this happened?

Variations

• Many different chemicals have different solubilities. By adding different amounts of salt, sugar or baking soda to water you can see how soluble each chemical is. Just add each chemical a teaspoon at a time to a glass of water until you notice that it no longer dissolves when you stir it around. Be sure to use the same amount of water for each experiment! The chemical that dissolves the most into the same amount of water is the most soluble, and the chemical that dissolves that least is the least soluble. Try it!
• How might temperature affect the solubility of a chemical? Try dissolving the same amount of sugar in hot water, room temperature water and ice-cold water. What happens? Can you think of other variables that might affect solubility?