Which among the following salts,solubility decreases with increase in temperature?

Tincture of iodine is

How many grams of water are required to dissolve $4 \ g$ of sodium sulfate at $323 \ K$? The solubility of sodium sulfate at this temperature is $16\%$.

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.

$CO_2$ gas is bubbled through water during a soft drink manufacturing process at $298 \ K$. If $CO_2$ exerts a partial pressure of $0.835 \ bar$,then $x \ mmol$ of $CO_2$ would dissolve in $0.9 \ L$ of water. The value of $x$ is $.....$ (Nearest integer).
(Henry's law constant for $CO_2$ at $298 \ K$ is $1.67 \times 10^3 \ bar$)

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 $25^{\circ} C$.