Solubility of iodine in water may be increased by adding

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

Henry's law constant for $CO_{2}$ in water is $1.67 \times 10^{8} \ Pa$ at $298 \ K$. Calculate the quantity of $CO_{2}$ in $500 \ mL$ of soda water when packed under $2.5 \ atm$ $CO_{2}$ pressure at $298 \ K$.

What type of solution is brass?

How many millimoles of $CO_2$ gas will dissolve when $CO_2$ gas is passed in $900 \ mL$ water at $298 \ K$ temperature? $[$ The value of $K_H$ is $6.02 \times 10^{-4} \ bar$ and partial pressure of $CO_2$ gas is $2 \times 10^{-8} \ bar.]$

Calculate the pressure of the gas if the solubility of the gas in water at $25^{\circ} C$ is $6.85 \times 10^{-4} \ mol \ dm^{-3}$. (Henry's law constant $K_H$ is $6.85 \times 10^{-4} \ mol \ dm^{-3} \ bar^{-1}$) (in $bar$)