Which of the following is a solution in which the physical states of solute and solvent are liquid and solid respectively?

Calculate the solubility of a gas in water at $260 \ mm \ Hg$ and $25^{\circ} C$ if Henry's law constant of the gas is $0.159 \ mol \ dm^{-3} \ atm^{-1}$ at $25^{\circ} C$.

At $293 \ K$,the Henry law constant in water for $N_2$ and $O_2$ are $76.48 \ kbar$ and $34.86 \ kbar$ respectively. What is the ratio of mole fractions of $N_2$ and $O_2$ in water? (Assume partial pressures of $N_2$ and $O_2$ are the same at $293 \ K$)

Which of the following statements is correct?

The solubility curve of $KNO_3$ in water is shown below. The amount of $KNO_3$ that dissolves in $50 \ g$ of water at $40^{\circ} C$ is closest to $.... \ g$

What is solubility? What is a saturated solution?