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Topic: I seemed to have done something wrong.  (Read 3102 times)

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Offline candysell

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I seemed to have done something wrong.
« on: April 06, 2014, 05:20:13 PM »
Determine the wavelength, in nanometers, of radiation with of 237kJ/mol energy?

My Answer:438nm

(273kj/mol)(1000J/1kj)(1mol/6.022*10^23)=4.533376615*10^-19 J

λ=hc/E
λ=(6.626*10^-34 J*s)(2.998*10^8 m/s)/(4.533376615*10^-19 J)
=.000000438m--->438nm

Apparently this is wrong so either I did this wrong or my homework is screwed up.

Offline Borek

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Re: I seemed to have done something wrong.
« Reply #1 on: April 06, 2014, 05:45:15 PM »
Looks OK to me.
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Offline candysell

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Re: I seemed to have done something wrong.
« Reply #2 on: April 06, 2014, 05:55:28 PM »
Looks OK to me.
If that's the case, then I can speak to my instructor about it to give me credit for this problem then.

Offline Borek

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Re: I seemed to have done something wrong.
« Reply #3 on: April 06, 2014, 06:10:46 PM »
http://www.wolframalpha.com/input/?i=energy+of+a+438nm+photon

Now just multiply by Avogadro's constant.
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Offline Big-Daddy

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Re: I seemed to have done something wrong.
« Reply #4 on: April 06, 2014, 06:40:04 PM »
237kJ/mol energy?

(273kj/mol)

Perhaps this is why?

Offline candysell

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Re: I seemed to have done something wrong.
« Reply #5 on: April 06, 2014, 06:44:04 PM »
237kJ/mol energy?

(273kj/mol)

Perhaps this is why?
Looks like I reversed the numbers.  I don't know how I missed that but thanks for catching that.  I should get it right now.

Offline Borek

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Re: I seemed to have done something wrong.
« Reply #6 on: April 06, 2014, 06:52:27 PM »
Sigh, I missed it too.
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Offline candysell

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Re: I seemed to have done something wrong.
« Reply #7 on: April 06, 2014, 06:59:59 PM »
Sigh, I missed it too.
Thanks.  You helped me confirm that my work was right but we do end up overlooking simple mistakes.  We're humans after all.

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