[helmich2]

Hi,

I'm trying to graph the temperature dependence for the partial pressure of SO2 gas over a 40% solution of NaHSO3 solution in a closed container at equilibrium.

I know I need to use Henry's Law, and NIST's Chemistry Webook gives:

k(T) = 1.4e^2900(1/T - 1/298) (among others)

I understand the equation, but it means the partial pressure of SO2 gas is going to go down as the temperature increases. Seems to me that the partial pressure of SO2 should increase. Am I misunderstanding the equation?

[blaisem]

It depends on how you define Henry's constant.  Check out Wikipedia for more information.

http://en.wikipedia.org/wiki/Henry's_law

Pay close attention to table 1 and the subscripts of k in the left most columns (not including column titled equation), then read the bit on temperature dependence of the Henry constant.

Hope that helps!

[helmich2]

Yeah, unit analysis works wonders. Figured it out about 2 h after posting. Needed to divide by the constant how NIST defines it.