Borax Crystals; Do different temperatures effect growth rates?

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

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• 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.

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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.

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• 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"

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• 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.

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

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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

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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.

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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.

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• 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.

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• 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?

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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.