Re: does an ice cube melt faster on the kitchen counter or in a glass of water

Hi Mary - You have asked an interesting question - I'll give you some hints for how you can experimentally find an answer:

Factors impacting how fast an ice cube melts on a kitchen counter or in a glass of water:

1. The temperature of the counter.
2. The *surface area* of the cube in contact with the counter.
3. The temperature of the water.
4. The surface area of the ice in contact with the water.
5. The amount of water surrounding the ice cube.
6. The temperature of the air surrounding the parts of the cube not touching the counter, or the water in a container.
7. The size and temperature of the ice cubes.
8. Contaminants in the water, such as salts or chlorination.

To take effect of temperature into account, I'm going to suggest you try your experiments in *temeprature controlled* environments, that way you'll be measuring the impact of surface contact vs. liquid contact, on the melting of the ice.

I'm also going to suggest that you use ice cubes made with the same volume of water that are the same shape. Filling the slots in an ice cube tray with equal amounts of water should give you nearly identical cubes.

Materials & Equipment:

• A 1 gallon (~3.8L) pot filled with water from the tap.
• A cutting or marble board.
• A refrigerator.
• An unheated oven.
• Ice cubes, fresh from the freezer.
• Timer.

Experiment 1:

1. The day before your experiment, do the following:
   1. Freeze your ice cubes.
   2. Put your cutting or marble board, and pot+water in the refrigerator to cool them to the same temperature.
2. The day of your experiment: leave the board and pot+water in the refrigerator.
3. Place an ice cube in the pot of water, and one on the board.
4. Start your time.
5. Check the ice cubes every 15-30 minutes (the melting process will progress slower in the refrigerator).
6. Note when the ice cube on the board melts, vs. the one in the pot of water.
7. Wipe off the board, and let it and the pot sit overnight in the refrigerator before testing again with new ice cubes (so you can obtain multiple measurements).

1. Repeat as above, but place your board and pot+water in an unheated oven. The insulated oven should keep both at a constant temperature during your experiment.
2. The melting will occur faster in the oven, so you may need to check every 15 minutes as the ice begins to melt.
3. Make multiple measurements over a few days, as in Experiment 1.

Experiment 3: Try having equal areas of the ice contact a solid surface, or a liquid surface. In the previous two experiments, the ice has had more contact with air when touching the counter surface, than it has when submersed in water. In some areas to search in our archives (listed below), you can learn that air is better insulator than water.

Repeat the above experiment using an ice cube on a glass surface, versus an ice cube in shallow glass dish with some water in the bottom.

Some things you might want to read about:

MadSci Archives: Query for how ice melts or heat of freezing ice water.

Ask your parents or teacher at school to go over some of the material in the files you'll locate with these searches, if they discuss things you have not yet had in school.

Have fun!

-L. Bry, MadSci Admin