I have tried for several hours to answer this question with no luck. I believe I may be missing a couple of steps or I am not utilizing the given information properly. Nonetheless, some guidance will be greatly appreciated.
The concentration of $\ce{N2}$ in the ocean at 25C is 445 $\ce{\mu}$M. The Henry's Law constant for $\ce{N2}$ is 0.61 x $\ce 10^{-3}$ mol $\ce L^{-1}$ atm $\ce L^{-1}$.
Part A:
Calculate the mass of $\ce{N2}$ in a liter of ocean water.
4.45 x $\ce 10^{-4}$ mol/kg = molality
$\ce{N2}$ in moles = 28.014 g/mol
Using Molality Equation
Molality = $\frac{amount of solute (mols)}{mass of solvent(kg)}$
I want kilograms, thus:
4.45 x $\ce 10^{-4}$ $\frac{mol}{kg}$ = $\frac{28.014 g}{mol}$
Where do I go from here?
Part B:
Calculate the partial pressure of $\ce{N2}$ in the atmosphere
Use C = K x $P_(gas)$
4.45 x $\ce 10^{-4}$ = (0.61 x $\ce 10^{-3}$ mol $\ce L^{-1}$ atm $\ce L^{-1}$)x
x = 0.73 atm