If $O_2$ gas is bubbled through water at $303 \; K$,the number of millimoles of $O_2$ gas that dissolve in $1 \; L$ of water is (Nearest Integer). (Given: Henry's Law constant for $O_2$ at $303 \; K$ is $46.82 \; kbar$ and partial pressure of $O_2 = 0.920 \; bar$). (Assume solubility of $O_2$ in water is too small,nearly negligible).

Calculate the solubility of gas in water at $1.2 \text{ atm}$ and $25^{\circ} C$ if Henry's law constant is $0.45 \text{ mol dm}^{-3} \text{ atm}^{-1}$ at $25^{\circ} C$.

Why are aquatic species more comfortable in cold water in comparison to warm water?

The air is a mixture of a number of gases. The major components are oxygen and nitrogen with approximate proportions of $20 \%$ and $79 \%$ by volume at $298 \ K$. The water is in equilibrium with air at a total pressure of $10 \ atm$. At $298 \ K$,if the Henry's law constants for oxygen and nitrogen are $3.30 \times 10^{7} \ mm \ Hg$ and $6.51 \times 10^{7} \ mm \ Hg$ respectively,calculate the mole fractions of these gases in water.

Assertion $(A)$: For an endothermic dissolution process,an increase in temperature increases the solubility in a nearly saturated solution.
Reason $(R)$: In a saturated solution,dynamic equilibrium exists between the dissolved solute and the undissolved solute.

Assertion: $A$ mixture of $He$ and $O_2$ is used for respiration for deep sea divers.
Reason: $He$ is soluble in blood.