At constant pressure,the volume of a fixed mass of an ideal gas is directly proportional to

$A$ gas occupies $10 \ L$ at $0 \ ^{\circ}C$ and $2 \ atm$ pressure. At what temperature will the pressure in the container be $2.5 \ atm$,assuming the volume remains constant (in $^{\circ}C$)?

State Charles' law in brief.

$A$ gas occupies a volume of $300 \, cc$ at $27 \, ^\circ C$ and $620 \, mm$ pressure. The volume of gas at $47 \, ^\circ C$ and $640 \, mm$ pressure is......$cc$

$A$ $100 \ L$ cylinder containing $H_2$ exerted a pressure of $4 \ atm$ at $300 \ K$. It was accidentally opened and some $H_2$ escaped. When it was closed,it exerted a pressure of $3 \ atm$ at $300 \ K$. The number of moles of $H_2$ remaining in the cylinder is equal to (Assume $H_2$ as an ideal gas; $R=$ gas constant)

When $48 \, L$ of dry $N_2$ gas is passed through $36 \, g$ of $H_2O$ at $27 \, ^oC$,the weight of water decreases by $1.20 \, g$. What is the vapor pressure of water in $atm$?