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Borax Crystals; Do different temperatures effect growth rates?

Anthony Hill 3 rd Period Science Fair 12/13/11. Borax Crystals; Do different temperatures effect growth rates?. Introduction/Background info. Chemist perform chemical reactions as a way to change one thing into another (something different)

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Borax Crystals; Do different temperatures effect growth rates?

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  1. Anthony Hill 3rd Period Science Fair 12/13/11 Borax Crystals; Do different temperatures effect growth rates?

  2. Introduction/Background info. • Chemist perform chemical reactions as a way to change one thing into another (something different) • The process of recrystallization, is one of the ways that Chemist perform these reactions. • When dissolving a mixture(s) in hot water, when the mixture(s), cools, you are left with what slowly appears as crystals.

  3. You, may want to know how the crystals appear, or why they do appear; and here is the answer to both questions. • It has to do with the simple fact that every solid that can be dissolved has a solubility, meaning the largest part of the solid will make a CLEAR solution. • When you start to see particles of the dissolved product, you can no longer dissolve more, UNLESS the solution is heated, then more of the product can be dissolved into the solution.

  4. Now, for the second question, why does the solution make a crystal. • When a hot solution is COOLED it suddenly has way to much of the original product in the solution than can be contained, by COOLED water. • Since it can no longer stay dissolved in the water, some "pieces" of the product "fall out" the solution; they then bump together, stick together, and form larger and larger pieces, these pieces are called crystals. • A crystal is a solid molecule of tiny little particles that can even be seen by a microscope, that have come together in a specific pattern.

  5. When molecules of crystals come together, impurities are created, they do not fit the layout, much like wrong pieces of a puzzle. • So if the crystal(s) form slowly enough, the impurities will be rejected out, because they do not fit the layout, and instead, they just remain in the solution and float away. • If a solution is cool to quickly, there is not enough time for the impurities and instead, get trapped in the crystals' structure, and the pattern is "disturbed"

  6. Think about the effects the speed of cooling might have on a crystal's size and clarity. • You can discover these answers by growing your own crystals with these products.

  7. Do you think that a crystal that is cooled to quickly, will look different from a crystal formed slowly?

  8. Hypothesis • My hypothesis is that, Yes the different temperatures will, effect the growth of the Borax crystals. I think they will grow best in the refrigerator

  9. Materials & Equipment • Large bowl (jars truthfully work best) • Water • Thermometer • Sting (pipe cleaners work best, because you can make shapes.) • String • Pencils (3), or Popsicle sticks

  10. Experimental procedures • 1. Write the hypothesis, on weather the crystals will grow best in, ice, refrigerator, or in room temperature. • 2. Prepare the ice bath, fill the large bowl half full of ice and then add water until the bowl is three-quarters full. • a) place the ice bath on a countertop or table, where it can be left undisturbed for about 5 hours. Then take the temperature.

  11. Materials & Procedures (continued) • Identical jars, or drinking glasses, of the large variety. • Pot with lid • Borax (also known as 20-mule team household cleaner) • Tablespoon • Plastic wrap • SAFETY NOTE: borax can cause allergic reaction, and is very harmful when swallowed.

  12. 4. Cut three pieces of string and tie on piece around each of your three pencils. Make sure the string is even to each other in length. • 5. Bring enough water to fill each jar three-fourths to boil. • 6. Add 1 tablespoon to e water ( in the jar), stir until dissolved. Repeat until no more Borax can be dissolved. • 7. Lay pencil with string tied on, across the top of the jar. (if using pipe cleaners, tie string around and hang the pipe cleaner in the solution) • 8. Place on in the refrigerator, on the countertop, and in the ice bath. • 9. Leave jars alone for about 5 hours, or until crystals completely cover pipe cleaner of string.

  13. **If ice melts in the ice bath, replace, make sure to keep the bowl about three-fourths full at all times. • 10. Carefully remove the pencil with string (and pipe cleaner) one at a time, record size and looks. • 11. Repeat step 10 till no more pencils can be removed. • How do your results vary from your hypothesis?

  14. Conclusion • In my conclusion, I have discovered that the crystals grew best in the refrigerator, I think this is correct because the temperatures does not change in the fridge, unless changed by a person. So, different temperatures do indeed effect the growth rates of Borax crystals.

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