Hi I was just wondering if you can help me out on this. Note: this isn't a homework question ok!

 

How you convert the wavenumber in cm^-1 into nm. I know if it said that you had to convert that wavenumber into nm^-1 it would be X 10^10. You people think that I might have to multiply it by 10^-10?

 

Any help appreciated.

Multiply by 10^7

well actually i was going through it last night and I figured that we have to convert the wavenumber into frequency in nm so I used the formula V(bar) = 1/Lambda and made lambda the subject and got lambda = 1/V(bar).

 

That was 1/16300 which equalled 6.134 x 10^-5 cm. To change it into the nm scale i simply divided it by the power of 10 to -15 and the final answer came as 6.134 x 10^-15.

 

Now I don't know if its the right answer or not but my head said it is.

Your head's wrong. nm are smaller than cm, so there should be more of them, so your answer doesn't even pass the "reasonability" test.

 

1 cm^-1 has a wavelength of 1 cm, which is 10^7 nm.

All the unit conversions are done in the same way, whether the unit is in the numerator or denominator.

 

For example, I would do this unit conversion like:

 

[math]\frac{1}{cm} \cdot \frac{1 cm}{10^7 nm} = \frac{1}{10^7 nm}[/math]

 

where the cm in the numerator and denominator cancel each other out. Note that since 1 cm = 10^7 nm, that the [math]\frac{1 cm}{10^7 nm}[/math] is equal to multiplying the term by 1.

o i see. I am shit in maths and just don't want to pay attention to some trivial things which i realise can be a disaster but i must get my acts straight in maths.