The oxygen dissolved in water exerts a partial pressure of \( 20 \, \text{kPa} \) in the vapour above water. The molar solubility of oxygen in water is _________ \( \times 10^{-5} \, \text{mol dm}^{-3} \).
(Round off to the Nearest Integer).
[Given : Henry's law constant \( = k_H = 8.0 \times 10^{4} \, \text{kPa} \) for \( \mathrm{O_2} \) , Density of water with dissolved oxygen \( = 1.0 \, \text{kg dm}^{-3} \) ]
