Take Home Lab #5

Take Home Lab #5:  Lifting and Ice cube with a String

Question: How does salt affect ice?

Safety: Dispose of all materials when finished. Do not consume any of the materials used in this activity. Clean up any spills immediately.

Materials: Ice cube, water, string, salt, sugar, one other soluble substance

Procedure: In this lab, you will be shown a discrepant event (an action that does not make much sense). Then you will be asked to try to figure out how it worked. You may use your book, information given in class, and the internet to figure out your answer. Remember that the internet may contain a lot of elementary and incorrect information. If you use the internet, be careful to analyze what you read and only depend on high school-level and well-known websites. If the website is the UCLA chemistry website, it is probably trustworthy. If it is little Johnny’s third-grade science fair project website, it probably is not reliable.

1. Put one large ice cube in an almost full cup of water so that it is near the top of the cup.

2. Lay a string across the top of the ice cube. Coil it in circles if possible.

3. Sprinkle salt on the string and ice cube and wait 10 seconds.

4. Now lift the ice cube out of the water.

5. Try this procedure again using sugar and at least one other soluble substance. (Such as kool aid, baking soda, powder laundry detergent) Tell whether each one had the same effect on the ice as the salt.

Wrap-Up

1. Write a paragraph describing what occurred when you used the salt, sugar and what other substance (name the substance when explaining) you used and attempted to lift the ice cube.

2. Write a 200-word (1/2 page) explanation for how this event works. Try to use some of the following terms in your explanation: freezing point depression, temperature, heat, heat of fusion, melting and freezing.