At a temperature of $300 \ K$,if the pressure of $0.09 \ mol$ of a gas is halved,what will be its volume?

Density of a gas is found to be $5.46 \, g / dm^3$ at $27^{\circ} C$ at $2 \, bar$ pressure. What will be density at $STP$?

$A$ certain mass of a gas occupies a volume of $250 \ mL$ at $2 \ atm$ pressure. Calculate the volume of the gas if the pressure is increased to $2.5 \ atm$ at a constant temperature. (in $mL$)

$A$ gas occupies $0.418 \ L$ at $27 \ ^\circ C$ and $740 \ mm \ Hg$ pressure. What will be its volume at $STP$ in $L$?

On a ship sailing in the Pacific Ocean where the temperature is $23.4^{\circ} C$,a balloon is filled with $2 \ L$ of air. What will be the volume of the balloon when the ship reaches the Indian Ocean,where the temperature is $26.1^{\circ} C$ (in $L$)?

State Charles' law in brief.