The volume and pressure of a balloon filled with hydrogen gas are $1 \ bar$ and $175 \ dm^{3}$. When the balloon reaches a certain height,its pressure decreases to $0.8 \ bar$. Calculate the new volume of the balloon. (in $dm^{3}$)

At $273 \, K$ temperature and $1 \, bar$ pressure,if the volume of a gas increases by $20 \%$,what temperature is required assuming pressure remains constant (in $, K$)?

Which of the following laws gives the relation between volume and temperature?

"Equal volumes of all gases at the same temperature and pressure contain equal number of particles." This statement is a direct consequence of

$A$ box contains $0.90 \ g$ of liquid water in equilibrium with water vapour at $27^{\circ} C$. The equilibrium vapour pressure of water at $27^{\circ} C$ is $32.0 \ Torr$. When the volume of the box is increased,some of the liquid water evaporates to maintain the equilibrium pressure. If all the liquid water evaporates,then the volume of the box must be $.... \ litre$. [nearest integer]
(Given $R = 0.082 \ L \ atm \ K^{-1} \ mol^{-1}$)
(Ignore the volume of the liquid water and assume water vapours behave as an ideal gas.)

$100 \, g$ of an ideal gas is kept in a cylinder of $416 \, L$ volume at $27^{\circ} C$ under $1.5 \, bar$ pressure. The molar mass of the gas is $.... \, g \, mol^{-1}$. (Nearest integer) (Given : $R = 0.083 \, L \, bar \, K^{-1} \, mol^{-1}$)