THE AMERICAN CHEMICAL SOCIETY CLEVELAND SECTION & NASA GLENN RESEARCH CENTER As part of the National Chemistry Week celebration (October 20 ‐ 26, 2013) Ask students in Grades 6 through 8 to investigate: “Ice: How long can it last?” Ice cubes melt when Energy, in the form of Heat, is absorbed and changes the Solid Ice to Liquid Water. Make Solid Ice as described below and carry out the tests to see how long you can make Ice last. Follow the instructions below and answer the questions. Materials: 













Ice cube tray, mini‐muffin tray, or medicine cups Tap Water Measuring spoons Measuring cups 1 Gallon Freezer storage plastic bag 4 ceramic saucers Large Stainless steel mixing bowl with flat bottom, or saucepan Block of wood, e.g., a cutting board or solid wood hot pad Styrofoam cup Plastic lid, large enough to cover top of Styrofoam cup Table top or floor lamp with a flexible or adjustable neck Ruler 60 W Incandescent bulb 13 W (60 W equivalent output) Compact Fluorescent bulb Adult help is required for these experiments! 1.
Make Solid Ice: a) Place the ice cube tray, mini‐muffin tray, or ten medicine cups on a level surface. NationalChemistryWeek–Contest2013
Page1
b) Fill each of the ten medicine cups or ten cups in the ice cube tray or mini‐muffin tray with 1 Tbsp of cold tap water. c) Place the ten medicine cups or tray in the freezer on a level surface (e.g., a baking sheet) for six hours or longer until frozen. d) Place ¼ cup, ½ cup, and 1 cup measuring containers on a level surface. e) Fill each of the three measuring cups with 1 Tbsp of cold tap water. f) Place the three measuring cups (with water) in the freezer on a level surface (e.g., a baking sheet) for six hours or longer until frozen. 2.
Remove Solid Ice: a) Fill the stainless steel mixing bowl with warm tap water. b) Remove the ice cube tray or mini‐muffin tray or medicine cups from the freezer and partially immerse the cups (one at a time if you are using medicine cups) in the warm water, making sure that no water gets inside the cups. Keep the bottom of the cups in the water for one minute, take them out of the water, and invert them to release the Solid Ice. If the ice cubes do not fall out, repeat the process until they are released. c) Collect the Solid Ice pieces as they fall out of the tray or medicine cups and add them to the Gallon Freezer Storage Bag. d) Remove Solid Ice pieces, as required for the experiments, and keep the rest in the Storage Bag in the freezer, until more pieces are required. Use only pieces that come out of the medicine cups or tray intact, i.e., without chipping or breaking. Repeat the process to Make Solid Ice and Remove Solid Ice if you require more ice pieces to complete the experiments. NationalChemistryWeek–Contest2013
Page2
3.
Make a table (on a sheet of paper) similar to the one below. Solid Ice ‐ Shape Solid Ice Start Time End Time Solid  Liquid Order (1‐4) Cube ¼ Cup ½ Cup 1 Cup Solid Ice ‐ Surface Solid Ice Start Time End Time Solid  Liquid Order (1‐4) Ceramic Stainless Steel Wood Styrofoam Cup (covered) Start Time End Time Solid  Liquid Order (1‐3) Solid Ice ‐ Light Solid Ice 60 W Incandescent Bulb 13 W Compact Fluorescent Bulb Direct Sunlight 4.
Solid Ice ‐ Shape: a) Place four ceramic saucers on a table, or other level surface. b) Take one ice cube out of the Freezer bag and place it on one saucer. Take the three ice cubes that were made in the measuring cups (i.e., the ¼ cup, ½ cup, and 1 cup measures) and place them on the three other saucers (one piece on one saucer). c) Record the time in the Start Time column of your table in the Solid Ice – Shape section. d) Starting after fifteen minutes, observe the Solid Ice pieces in the four saucers. Continue to observe them every five minutes thereafter. NationalChemistryWeek–Contest2013
Page3
Record the time at which each piece melts completely in the End Time column of your table for the specific piece, e.g., record the time when the ¼ cup piece melts in the End Time column for the ¼ Cup row. e) After all four ice pieces have melted completely (and become Liquid Water), mark the order in which the pieces melted in the Solid  Liquid Order column. Write 1 for the piece that melted first, 2 for the piece that melted next, and so on. 5.
Solid Ice ‐ Surface: a) Place a ceramic saucer, the stainless steel bowl, the block of wood, and the Styrofoam cup on a table, or other level surface. b) Take four ice cubes out of the Freezer bag. Place one ice cube on the ceramic saucer. Turn the stainless steel bowl upside‐down and place one ice cube on top of the over‐turned bowl (in the middle so it will not slide down the side). Place one ice cube on the block of wood. Place one ice cube inside the Styrofoam cup and place the plastic lid on top. c) Record the time in the Start Time column of your table in the Solid Ice – Surface section. d) Starting after fifteen minutes, observe the Solid Ice pieces in the four saucers. Continue to observe them every five minutes thereafter. Record the time at which each piece melts completely in the End Time column of your table for the specific piece, e.g., record the time when the ice cube on the upturned stainless steel bowl melts in the End Time column for the Stainless Steel row. e) After all four ice cubes have melted completely (and become Liquid Water), mark the order in which the cubes melted in the Solid  Liquid Order column. Write 1 for the cube that melted first, 2 for the cube that melted next, and so on. 6.
Solid Ice ‐ Light: Adult help is essential for this section! a) If a table lamp is used, place it on a table or other level surface. After making sure that the table or floor lamp is not plugged into an electrical outlet, fit the 60 W Incandescent bulb in the socket. b) Point the bulb of the lamp downwards and use the ruler to position a saucer about 2 inches below the bottom of the bulb. Use a book or stack of paper towels to raise the saucer to the correct height. NationalChemistryWeek–Contest2013
Page4
c) Plug in the lamp, turn it on, and leave it undisturbed for 5 minutes. d) Place an ice cube on the saucer and record the time in the Start Time column and 60 W Incandescent Bulb row in the table. e) Starting after fifteen minutes, observe the Solid Ice piece in the saucer. Continue to observe it every five minutes thereafter. Record the time at which the piece melts completely in the End Time column of your table in the 60 W Incandescent Bulb row. f) Turn off the lamp and allow it to cool for at least 30 minutes. Unplug the lamp and remove the 60 W Incandescent bulb and fit the 13 W Compact Fluorescent bulb into the socket. g) Repeat steps b) and c). h) Place an ice cube on the saucer and record the time in the Start Time column and 13 W Compact Fluorescent Bulb row in the table. i) Starting after fifteen minutes, observe the Solid Ice piece in the saucer. Continue to observe it every five minutes thereafter. Record the time at which the piece melts completely in the End Time column of your table in the 13 W Compact Fluorescent Bulb row. j) Turn off and unplug the lamp. k) Place an ice cube on a saucer on a window sill or other level surface (e.g., a table) such that the ice is in direct bright sunlight. Record the time in the Start Time column and Direct Sunlight row of the table. l) Observe the Solid Ice piece every five minutes and record the time at which it melts completely in the End Time column and the Direct Sunlight row of the table. m) List the order in which the ice melted for the three light sources (two bulbs and sunlight) in the Solid  Liquid Order column. Write 1 for the cube that melted first, 2 for the cube that melted next, and so on. NationalChemistryWeek–Contest2013
Page5
Questions: 1. In the Solid Ice – Shape experiment, which ice piece melted first? Can you explain why this shape melted faster than the other shapes? 2. In the Solid Ice – Light experiment, did you notice a difference in how fast the two light bulbs (incandescent of compact fluorescent) melted the ice cubes? Please explain your answer in terms of energy efficiency. 3. If you had to choose among the light bulbs and direct sunlight as an indoor light source that would also keep your house cool, which one would be best? Please explain your answer. 4. If you wanted your house to be energy efficient, which of the three materials tested in the Solid Ice – Surface experiment (stainless steel, ceramic, or wood) would work the best if used on the outside of the house? Explain why your choice would be effective in keeping your house cool in the summer and warm in the winter. 5. If you touch a stainless steel bowl and a ceramic saucer, do you notice a difference, e.g., one ‘feels cooler’ than the other? Can you provide an explanation for this observation and use it to explain the results of the Solid Ice – Surface experiment? To complete your entry send us: a. Written answers to all the questions and your Table. b. Please complete the entry form (Chemistry Contest Entry Form—found on this web site) and attach it to your entry. Entries should be postmarked by Friday, November 8, 2013. c. Send your entry with a self‐addressed stamped envelope (refer to Chemistry Contest General Information—also found on this web site for details) to: Dr. Mark Waner Department of Chemistry John Carroll University 1 John Carroll Boulevard University Heights, Ohio 44118 NationalChemistryWeek–Contest2013
Page6