Identify a pair of gases from the following that does not obey Henry's law.

If the solubility of $NaCl$ at $20\,^{\circ}C$ is $35\,g$ per $100\,g$ of water,then on adding $50\,g$ of $NaCl$ to the same amount of water at the same temperature,the amount of salt that remains undissolved is .......... $g$.

Dry air contains $79 \% \,N_2$ and $21 \% \,O_2$. At $T \,K$, if Henry's law constants for $N_2$ and $O_2$ in water are $8.57 \times 10^4 \,atm$ and $4.56 \times 10^4 \,atm$ respectively, the ratio of mole fractions of $N_2$ and $O_2$ dissolved in water at $1 \,atm$ is

If $N_2$ gas is bubbled through water at $293 \ K$,how many moles of $N_2$ gas would dissolve in $1 \ litre$ of water? Assume that $N_2$ exerts a partial pressure of $0.987 \ bar$. [Given $K_{H}$ for $N_2$ at $293 \ K$ is $76.48 \ kbar$]

Calculate the solubility of a gas having partial pressure $0.15 \ bar$ at $25^{\circ} C$.
$[K_{H} = 0.16 \ mol \ dm^{-3} \ bar^{-1}]$

Observe the following data given in the table $(K_H = \text{Henry's law constant})$. The correct order of solubility of these gases is:

Gas	$K_H$ (kbar at $298 \ K$)
$CO_2$	$1.67$
$Ar$	$40.3$
$HCHO$	$1.83 \times 10^{-5}$
$CH_4$	$0.413$