Growing Crystals From A Melt Worksheet (Page 2 of 4) in pdf

5. Use the crucuible tongs to remove the watch glass by gently placing one side

of the tongs under the side of the watch glass and the other on top. Carefully

close the tongs to get a firm grip and lift the watch glass of the hot plate.

Move the glass with the melted material over to the ice cubes and carefully

place the watch glass on top of the ice. Hold it there to keep it from sliding

off. Focus your camera on the liquid in the center of the watch glass. Keep

careful track of when the first crystal appears and when the last of the liquid

solidifies, so that you can calculate total elapsed time from liquid to solid.

Part 2: Intermediate cooling.

1. Place one of your watch glasses with the Salol on it just on the surface of the

hot plate. Do not push it in toward the center. You need to be able to

remove it with the tongs as soon as the solid melts completely. Watch the

glass and solid carefully, as soon as the material is completely melted start

your stop watch or clock.

2. Use the crucuible tongs to remove the watch glass by gently placing one side

of the tongs under the side of the watch glass and the other on top. Carefully

close the tongs to get a firm grip and lift the watch glass of the hot plate.

Move the glass with the melted material over to the lab table top and

carefully place the watch glass on the tabletop.

3. Have another student or pair keep track of the second watch glass. As soon

as the first set of crystals has completely formed, refocus the camera on the

new melt and follow the crystallization process for this sample.

4. Be sure to record the end time for crystallization so that you can calculate the

total elapsed time for this sample.

Part 3 : Slow Cooling

5. 1. Place one of your watch glasses with the Salol on it just on the surface of

the hot plate. Do not push it in toward the center. You need to be able to

remove it with the tongs as soon as the solid melts completely. Watch the

glass and solid carefully, as soon as the material is completely melted start

your stop watch or clock. IMMEDIATELY UNPLUG THE HOTPLATE!!!

6. Do not remove the sample from the hotplate. Your sample will cool at the

same rate as the hot plate!

7. When the second sample has completely crystallized, refocus your camera on

the sample left on the hot plate. While waiting for the final sample to cool,

you may proceed to the analysis and conclusion section to start completing

the Part 1 and 2 data collection.

Growing Crystals From A Melt Worksheet Page 2