At what pressure will a quantity of gas,which occupies $100 \ mL$ at a pressure of $720 \ mm$,occupy a volume of $84 \ mL$?

At $200 \ K$,an ideal gas $(X)$ present in a $1 \ L$ flask has a concentration of $1 \ mol \ L^{-1}$. At the same temperature,$0.1 \ mol$ of $X$ is added into the vessel. What is the final pressure of the gas in $atm$?
(Given $R = 0.082 \ L \ atm \ mol^{-1} \ K^{-1}$)

State Charles's Law.

$34.05 \ mL$ of phosphorus vapor weighs $0.0625 \ g$ at $546 \ ^oC$ and $0.1 \ bar$ pressure. What is the molar mass of phosphorus (in $g/mol$)?

$n$ moles of an ideal gas at temperature $T$ (in kelvin) occupy $V \ L$ of volume, exerting a pressure of $P$ atmospheres. What is the concentration (in $mol / L$)?

At $127 \, ^oC$ temperature,the volume of a gas is $3 \, L$. If the volume of the gas becomes half at constant pressure,calculate the final temperature in Kelvin. (in $, K$)