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Topic: Specific Rotation of 1330 degrees???  (Read 3939 times)

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Offline NighStalker

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Specific Rotation of 1330 degrees???
« on: July 07, 2009, 08:51:43 PM »
I am solving a problem for my organic chem lab and here are the values given
160 mg of an organic compound
dissolved in 8 mL of water
the solution place in a 10 cm polarimeter
Value obtained is +26.6 degrees. Calculate the specific rotation for the compound.

HERE IS WHAT I DID:
c = mass/volume = 0.160 g/8 mL = 0.020 g/mL
l = 10 cm = 1 dm
[α] = (+ 26.6 °)/(0.020 g/mL ×1 dm)
[α] = + 1330 °

so my final answer is 1330 degrees, is that even normal? Could 1330 also be stated as +250?

Offline sjb

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Re: Specific Rotation of 1330 degrees???
« Reply #1 on: July 08, 2009, 02:28:07 AM »
I am solving a problem for my organic chem lab and here are the values given
160 mg of an organic compound
dissolved in 8 mL of water
the solution place in a 10 cm polarimeter
Value obtained is +26.6 degrees. Calculate the specific rotation for the compound.

HERE IS WHAT I DID:
c = mass/volume = 0.160 g/8 mL = 0.020 g/mL
l = 10 cm = 1 dm
[α] = (+ 26.6 °)/(0.020 g/mL ×1 dm)
[α] = + 1330 °

so my final answer is 1330 degrees, is that even normal? Could 1330 also be stated as +250?

Nothing wrong with a specific rotation of over 360°, but no +1330 is not the same as +250 (or -110, or ...)

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