The statement “If $0.003 \ mol$ of a gas are dissolved in $900 \ g$ of water under a pressure of $1 \ atm$,$0.006 \ mol$ will be dissolved under a pressure of $2 \ atm$”,illustrates:

Solubility of iodine in water may be increased by adding

The Henry's law constant for the solubility of $N_2$ gas in water at $298 \ K$ is $1.0 \times 10^5 \ atm$. The mole fraction of $N_2$ in air is $0.8$. The number of moles of $N_2$ from air dissolved in $10 \ moles$ of water at $298 \ K$ and $5 \ atm$ pressure is

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Helium is used to dilute oxygen in diving apparatus.
Reason $R$: Helium has high solubility in $O_2$.
In the light of the above statements,choose the correct answer from the options given below:

If four gases $A$,$B$,$C$ and $D$ have Henry's constant $(K_H)$ values $1.9 \times 10^1 \ bar$,$6.5 \times 10^{-4} \ bar$,$7.8 \times 10^{-4} \ bar$ and $6.0 \times 10^3 \ bar$ respectively,then which of the following gas has maximum solubility at the same partial pressure?

What kind of attractions are present in an aqueous solution of $NaCl$?