Chemistry Problem (Energy Levels)

ste.kelehan

I am studying for a chemistry exam in collage! I haver never done chem before or been to a lecture!

The Question is: The characteristic yellow/orange light emitted from sodium vapour street lamps arises from two closely spaced lines with wavelengths of 589.59 nm and 588.99 nm. The two transitions are to a common lower state. What are the energies of the two transitions, and what is the energy difference between the two upper states? Give your answer in eV and in J mole-1.

Do you use E=(planks constant)c/(lamda) and 1/(lamda)=R(1/n^2-1/m^2)?
I dont know where I can include sodium?

Thanks

harmonisch

E=hf and f=c/λ are the equations needed f (frequency), c(speed of light), h(plank's constant) and λ(the wavelength)
use the equations to find E for the two wavelengths given, this gives you the energies of the two tramsitions. Then subtraction of those two answers will give you the answer to the last part

ste.kelehan

Yeah I did that! It just seems to simple?

harmonisch

Well that's all there is to it, it is good that you are finding it easy! Good luck in your exam!!

ste.kelehan

Okay thanks a mill!

ste.kelehan

Any one know how to do this question?

Barium Sulfate (BaSO4) is practically insoluble in water. Estimate the mass of BaSO4 that will be produced when 100ml of a 2M solution of Ba(NO3)2 in water is added to 100ml of a 2M solution of Na2SO4 in water.

Thanks!

spurious

Why don't you attend lectures and do your own work?

Peregrine

At least make an effort.

Also, this is the Leaving Cert forum.