Melting Points

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Melting Points

• You will do MANY in organic labs.
• Learn to do them well.

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• Prepare THREE samples
• Pure sample A
• Pure sample B
• Pure sample of the Unknown

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Insert the capillaries into the 3 slots,and
select a desired setting, -- say about 5.

• View the samples through the observation window
  and watch as they melt. Record the results.

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• Next, prepare the
• 7525 5050 and 2575
• mixtures of A and B in the following manner.

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Grind approx. equal amounts of samples A and B

• Make a row of each, and divide each into five
  approximately equal portions with your spatula.

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Scrape together the portions as shown below.

• Grind each mixture together to obtain fine
  powders.

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This provides the mixtures you need for your
mixed M.P.s

• Prepare capillaries for each of the three
  mixtures and prepare to take their M.P.s on the
  Mel Temp

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• Allow the Mel Temp to cool down to a temperature
  of about 100 degrees celsius.
• Determine the melting points of these three
  mixtures.
• Record the melting RANGE of
• each.

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• Finally, prepare about 5050 mixtures of
• (1) Known sample A mixed with the Unknown.
• (2) Known sample B mixed with the Unknown.
• Determine the melting RANGE of each mixture.
• You have made three M. P. runs --
• and
  YOURE DONE!

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If you are in my section, check the bulletin
board to see if you are on CLEAN-UP.

• Record the name(s) of your partner(s) on your
  Laboratory Report and turn it in before you
  leave.
• Complete the write-up in your Lab notebook. If
  you are in my section, I must have your notebook
  by 200 pm Friday.