Henrys law constant

The Henry's law constant for oxygen in water at $298K$ is $4\mathrm{.}5{10}^{4}at\frac{m}{m}ol$ fraction. Determine the saturation concentration of oxygen in water exposed to dry air at $298K$ and $1$atm.$[8\mathrm{.}32m\frac{g}{L}]$