Rydberg Formula

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Claire_Kim_2F
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Rydberg Formula

Postby Claire_Kim_2F » Tue Oct 20, 2020 10:36 am

Good afternoon,
I was confused on question 6 from the homework because for the wavelength range in nanonometers do you plug in 6 and 1 into Rydberg's formula 1/λ = RZ^2(1/n1^2 - 1/n2^2) for the longest gap and then 6 and 5 in for the shortest gap?

Arielle Sass 2A
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Re: Rydberg Formula

Postby Arielle Sass 2A » Tue Oct 20, 2020 1:25 pm

Hi, you're right! That's how I solved this equation.
Using v=R[1/n12-1/n22], I first input n1=5 with n2=6, and then I input n1=1 with n2=6.
I initially kept getting this question wrong, but I realized it was because of a mistake with the Sig Figs that Sapling used... the only way it accepted my answer was when I used only one sigfig for my minimum wavelength two for my maximum wavelength.
I don't know if everyone had that issue or just me though!

emmaferry2D
Posts: 118
Joined: Wed Sep 30, 2020 9:47 pm

Re: Rydberg Formula

Postby emmaferry2D » Tue Oct 20, 2020 2:40 pm

Arielle Sass 1L wrote:Hi, you're right! That's how I solved this equation.
Using v=R[1/n12-1/n22], I first input n1=5 with n2=6, and then I input n1=1 with n2=6.
I initially kept getting this question wrong, but I realized it was because of a mistake with the Sig Figs that Sapling used... the only way it accepted my answer was when I used only one sigfig for my minimum wavelength two for my maximum wavelength.
I don't know if everyone had that issue or just me though!

What did you put in for 'R'
In the book it says 3.29*10^15 but on the homework it was saying to put 1.09*10^7 so i was confused

Arielle Sass 2A
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Re: Rydberg Formula

Postby Arielle Sass 2A » Tue Oct 20, 2020 5:45 pm

Use the value 3.29x10^15 Hz for Rydberg's formula when using the equation v=R[1/n12-1/n22]. I noticed that the equation you used was "1/λ = RZ^2(1/n1^2 - 1/n2^2) and so maybe for that equation, R is different (though I've never seen that equation so I don't exactly know where it comes from). But when using the equation I mentioned before, which is the equation Dr. L gave to us so I'd recommend using that one, R should be 3.29x10^15.

AnnaNovoselov1G
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Re: Rydberg Formula

Postby AnnaNovoselov1G » Tue Oct 20, 2020 8:33 pm

When using the equation 1/λ = RZ^2(1/n1^2 - 1/n2^2) , you would plug in R=1.097 x 10^7/m.
When using the equation v=R[1/n12-1/n22, you would plug in R= 3.29 x 10^15 Hz.

I think there are different variations because the units are different.

I found that this question was also asked on Chem Community in 2014. Here's the link: viewtopic.php?t=4054

hope this helps!

Adrienne Yuh 2B
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Joined: Wed Sep 30, 2020 10:03 pm

Re: Rydberg Formula

Postby Adrienne Yuh 2B » Tue Oct 20, 2020 8:49 pm

There are different variations of R online and in the textbook, but the one the professor gave us is relative to frequency, R=3.29*10^15.

emmaferry2D
Posts: 118
Joined: Wed Sep 30, 2020 9:47 pm

Re: Rydberg Formula

Postby emmaferry2D » Sun Oct 25, 2020 12:16 pm

AnnaNovoselov1G wrote:When using the equation 1/λ = RZ^2(1/n1^2 - 1/n2^2) , you would plug in R=1.097 x 10^7/m.
When using the equation v=R[1/n12-1/n22, you would plug in R= 3.29 x 10^15 Hz.

I think there are different variations because the units are different.

I found that this question was also asked on Chem Community in 2014. Here's the link: viewtopic.php?t=4054

hope this helps!

thank you this was helpful!


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