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 $25^{\circ} C$.

Assertion : When a salt such as $NaCl$ dissolves,the $Na^{+}$ and $Cl^{-}$ ions leaving the crystal lattice acquire far greater freedom.
Reason : In thermodynamic terms,the formation of solution occurs with a favourable change in free energy,i.e.,$\Delta H$ has a high positive value and $T\Delta S$ a low negative value.

Why is a soda water bottle kept in a cold place?

Given the solubility curves of $KNO_3$ and $KCl$,which of the following statements is not true?

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 $293 \ K$)

$(a)$ Explain the following phenomena with the help of Henry’s law.
$(i)$ Painful condition known as bends.
$(ii)$ Feeling of weakness and discomfort in breathing at high altitude.
$(b)$ Why does a soda water bottle kept at room temperature fizz on opening?