Create Your Own Snow Globe

Purpose To create an attractive snow globe using household materials while reinforcing the concepts covered in our chemistry unit: Solubility Solvent/Solute Solution Saturated/Unsaturated Solution Suspension Polar/Non-Polar Compounds “Like – Dissolves – Like” Ionic Compounds (ionic bonds) Molecular Compounds (covalent bonds)

Materials 5 test tubes ( 9 cm in height) Stoppers Test tube rack 150 ml beakers Water Baby oil Mineral oil Vegetable oil Coarse/kosher salt sugar Measuring spoons Stopwatch 4 oz. baby food jar, empty, clean and dry Small object that you would like inside your snow globe Hot glue gun and glue sticks

Test Liquid (Solvent)/Solid (Solute) Combinations PROCEDURE: Label the 5 test tubes: Water/sugar water/salt veg. oil/salt Mineral oil/salt Baby Oil/salt Test each “solvent-solute” combination to determine suitability for your snow globe

1. Pour your solvent into beaker, use it to fill test tube to about 1 cm from the top. 2. Put a level teaspoon of solute into the test tube. 3. Put stopper into test tube and shake the test tube to mix.

4. Do the solvent and solute form a solution or suspension 4. Do the solvent and solute form a solution or suspension? If a solution has formed, continue with step 5. If a suspension has formed go to step 6.

Add additional solute, one scoop at a time, until a suspension forms Add additional solute, one scoop at a time, until a suspension forms. (Be sure to shake test tube every time a scoop is added before you add more. Shake the test tube and turn over, using stopwatch, measure the time it takes for all of the solute to fall to the bottom. Record the time on the data table under trial 1. Repeat this step two more times for trials 2 and 3.

7. Calculate the average time using: T (avg.) = Time 1 + Time 2 + Time 3 (sec.) 3 8. Calculate the speed of snow fall using: Speed = Height of test tube (cm/sec) T (avg.)

Rate of Snowfall vs. Mixture Record results in data table. Solvent/Solute Height of Test tube (cm) Time (sec.) Trial 1 Trial 2 Trial 3 T(avg.) (sec.) Speed (cm/sec.) Water/sugar 9 Water/salt Veg. oil/salt Min. Oil/salt Baby Oil/salt

What makes a successful Snow Globe? Consider the following: The liquid (solvent) you will choose: water (polar), baby oil (non-polar), mineral oil (non-polar), vegetable oil (non-polar) The solid (solute) to represent snow: salt (ionic), sugar (polar)

The solubility of your solvent and solute combination: polar/polar, polar/ionic, non-polar ionic Solution Suspension Recall that “like – dissolves – like”, that is, a polar solvent can dissolve a polar (or ionic) solute, however, a non-polar solvent cannot dissolve a polar (or ionic) solute. In this case a suspension will form, hence potential snow globe materials.

Finally Snow should fall slowly and gently, consider the viscosity of your solvent and the speed of snow fall.

Final Step Assembling Your Snow Globe Now that you have determined the ideal solvent/solute combination, it’s time to assemble your snow globe. Plug in hot glue gun and allow it to preheat. Place your object in the center of the inside of the jar lid and place jar over the lid to make sure it will fit. Glue your object to the inside of the jar lid, allow to dry and harden before continuing.

Fill jar with solvent Add two teaspoons of solute to the solvent. Run a bead of glue around inside of jar lid and quickly attach lid to the jar, this will prevent leaking when you turn the jar over. Allow enough time for the glue to cool and harden before turning the snow globe over.

Congratulations! You’ve made your very own snow globe.