Growing Salt Crystals

1. Growing Salt Crystals Beth Fugett Augusta High School 9th grade Science March 4, 2002

2. Table of Contents • Introduction • Background Information • Experiment • Procedure • Data • Discussion & Data Analysis • Conclusion • Acknowledgments • References

3. Introduction How does salt melt ice? I really wanted to figure this out, but before I could I had to get salt. Instead of just buying it I decided to make it. I didn’t know how to go about doing it so I researched. I also decided to put the salt in cold water as well as room temperature water. I thought that the colder water wouldn’t grow as much salt as the room temperature water. I decided this because when you put salt on ice it melts the ice, not freezes. I hoped to figure out what water temperature as to do with salt growth in the oceans. By putting salt and water in glasses and keeping one could, I thought I would get a pretty good answer.

4. Background Info. Crystals are grown only when the conditions are just right. That is why most crystals that are grown aren’t perfect. Ice crystals are formed when molten volcanic rock cools and crystallizes.They can also grow from a solution. It happens when one substance is dissolved in a solution and they start to connect and crystallize. Sea water is a solution. Crystals are solids that have arranged atoms in a repeating, orderly pattern. Some crystals are made up of entirely one kind of atoms whereas some are made up of certain atoms called ions. Table salt is made special. After they mine it, they sort it for quality, then crush.

5. Experiment Dependant Variable: The amount of salt crystals grown in each glass. Materials: 1/2 cup salt 1 cup water 4 toothpicks 2 glasses 1 spoon 6 in. of string Independent variable: The temperature of the water. Constant: The amount of water and salt put in each glass and the amount of time taken to do the experiment. Control: The room temperature water with 1/4 cup salt and 1/2 cup of water.

6. 1. Put 1/2 cup of water in each glass 2. Set one in the refrigerator and one somewhere at room temp. 3.Take 2 toothpicks and tape them together the width of the glass. 4.Cut your string in half and tape it to the toothpicks. 5. Do the same with the other toothpicks and string. 6. Take the glasses out after one or two days. 7. Put 1/4 cup salt in each glass and stir until completely dissolved. 8. Put toothpicks across the glass so the string dangles in the water. 9. Then, put the glass back where they were and over the next few days record what you see. Procedure

7. Data

8. Discussion and Data Analysis • Which glass grew the most crystals? • Why? • Data related to hypothesis. • Changes • Data related to table

9. Conclusion Even though I didn’t learn what I wanted to, I still learnt a lot. The cold atmosphere around the glass made the crystals grow slower than the room temperature crystals. My hypothesis was in a way correct. The cold water grew slower crystals. I can’t relate this to the ocean in a fool proof way because the conditions of nature are very different than the controlled ones in an experiment.

10. Acknoledgements Many people helped me with finding and organizing my experiments. Mr. Radloff helped me get new ideas and helped me stay on task. My parents bought the supplies and kept my sister and brother away from it. I didn’t use any businesses because there wasn’t a need for them. So thank you for all your help.

11. References • World book, 17, salt, Chicago, World Book Inc., 2002, 72-75 • The New Book OF Knowledge, 3, Chicago, Groiler Incorporated, 1991, 591-593 • www.webmineral.com/crystal.shtml