Properties of Oceans and Freezing Properties of Water

Question

The physical properties of water make it a very unusual substance and determine many of the properties of the oceans. Here are two simple experiments that can help us investigate how things dissolve in water and how water freezes.

Materials:

4 glasses (8 to 12 oz.), water, salt, food coloring

Procedure:

1. Mix a saturated solution of salt water by adding several tablespoons of salt to a glass of water. Stir it and let it settle for five minutes. There should be undissolved salt on the bottom of the glass. Pour the salt water into another glass until it is 2/3 full, taking care to leave the undissolved salt in the first glass.

2. Fill the 2 remaining glasses to about 2/3 full using tap water for one and tap water with 3 or 4 drops of food coloring for the third. Make sure all three glasses are filled to the same level.

3. Place the glasses in the freezer.

4. Record observations at half hour intervals until no more changes are recorded.

Discussion:

Report your results. Discuss what happened and give scientific explanations for what you observed. Based on what you know about the characteristics of water try to explain the differences between the way the salt and the fresh water froze. Describe what happened to the food coloring and explain the results. How do your results relate to our study of the oceans?

Summary

This question belongs to ocean science and discusses about physical properties of oceans.

Word count: 250