Borax Crystal lab Mrs.Lalonde
How To Grow a Borax Snowflake
Do real snowflakes melt too quickly? Grow a borax snowflake, and enjoy the sparkle all year long!
Topics:Solutions, solutes, solvents
Materials:
String (about 5 inches) Large beaker (400 or 600 mL)
Pipe cleaners Borax Popsicle stick Hotplate
Thermometer Glass stir rod Hot hands Scissors
Prelab:
1. This lab requires about 16 g borax for every 100 mL of H2O. Calculate the approximate amount of borax that you will need if you use 300 mL of water or if you use 450 mL of water. Show your work.
Procedure:
1. Start heating your water. Fill the beaker about 3/4 full. Heat the water on the hotplate at the highest setting. Do other steps while this is heating, but make sure one partner constantly monitors the water. When the water temp reaches 80°C, turn down the setting so the water does not quite boil.
2. Cut a pipe cleaner into three equal sections.
3. Twist the sections together at their centers to form a six-sided snowflake shape. Trimor fold back the edges so the snowflake fits easily inside the beaker.
4. Tie the string to the end of one of the snowflake arms. Tie the other end of the string to the popsicle stick and set it aside for step 7.
5. Gather enough borax to saturate the solution (plus maybe a bit extra). See pre-lab calculations.
6. Add your borax to the warming water, stirring with the stir rod (never the thermometer!) to dissolve it. Continue until the water is at least 80 degrees and the borax isfully dissolved.
7. Lay the stick across the top of the beaker. Roll the string around the stick until the snowflake hangs just above the bottom of the beaker without touching.
8. Allow the beaker to sit in an undisturbed location overnight. As the solution cools, the solubility of borax decreases. The solution will become saturated and the extra solute will come out of solution and form crystals on the pipe cleaners!
9. Cleanup: Return your scissors. Return all materials. If you spilled on your hot plate, you may need to clean it… you will need to cool it off with some water first!
Write-up:
1. Identify the solute and solvent in this lab.
2. Define solution.
3. What is meant by a saturated solution?
4. When you dissolved the borax in the hot water do you think you made a saturated solution? Explain.
5. Is the solution you made (without the ornament) heterogenous or homogenous?
6. In your own words hypothesize what will happen when the temperature decreases? Why?
7. Can you think of another example where you heat up a liquid to help dissolve it?