[Sloppyboy]

Water in the atmosphere ~.33% by weight is responsible for about 70% of all atmospheric absorption of radiation. This contributes signficantly to the greenhouse effect, ensuring a warm, habitable planet. Liquid water has an absopriton band at 1640 cm-1. What ist the wavelength of this light in nanometers? What is the energy in Joules? If one mole of h20 absorms one mole of photons at this wavelength, how much energy is absorbed? What type of process occurs when a molecular absorbs light in thsi region of the spectrum?

I honestly dont know where to start with the question. I've been going to it for 45 min in the book, but if anyone can guide me to what to do with the given information I would be grateful!! Thanks!

[Arkcon]

I hope you're not getting bogged down with the trivia in the description of this word problem. What formulas relate wavenumber to wavelength?  And wavelength to energy?  And check your text for the definition of the process described --we can't "help" you figure this definition out, you either find it in your text or you don't.

[Sloppyboy]

I already know all those equations by heart but I dont know what to do with the given info. What can i do with the absorption band at 1640 cm-1? I know I have to use the equation a=-log(t) , but i honestly have no clue what to do with the given info..how does ~.33% by weight factor in? a small start with some guidelines for the info will be helpful...i dont need anyone to actually give me the answers...

[Sloppyboy]

Alright since no one is helping me and ive been trying to do this for the past hour +...im assuming that the absorption band is the wave number...then i use the equations...anyone want to correct me or tell me im right? Thanks!

[sjb]

Alright since no one is helping me and ive been trying to do this for the past hour

I'm not surprised no one was helping you, it was gone midnight very early Monday morning here...

Your approach seems fine though.