[lamourj]

  Hi  I am a littlebit puzzled as why is a soluble gas in water is more soluble in cold water than it is in warmer water?  Can somebody explain?

Thanks

[Dan]

I'm not sure if this is the textbook explanation, but this makes sense to me:

[D = capital delta]

Consider the process of dissolved gas escaping

A_(aq) ---> A_(g)

now, think about DG for this process:

DG = DH - TDS

The more negative the value of DG, the more favourable the process. Think about the sign of DS (entropy change). Is it + or -? In which case, what effect will lowering the temperature (T) have on DG (assuming DH is temperature independant)?