An open vessel containing air was heated from $27^{\circ} C$ to $727^{\circ} C$. Some air was expelled. What is the fraction of air remaining in the vessel? (Assume air as an ideal gas)

$A$ vessel contains $1.6 \ g$ of dioxygen at $STP$ ($273.15 \ K$,$1 \ atm$ pressure). The gas is now transferred to another vessel at constant temperature,where pressure becomes half of the original pressure. Calculate
$(A)$ volume of the new vessel.
$(B)$ number of molecules of dioxygen.

$A$ gas occupies $600 \ mL$ at $27 \ ^\circ C$ and $730 \ mm$ pressure. What will be its volume at $STP$ in $litres$?

At $400 \, K$ temperature,$200 \, mL$ of $N_2$ gas has a pressure of $1.5 \, bar$. Find the volume of $N_2$ gas at $STP$. (in $, mL$)

For a fixed amount of gas at constant pressure,provide the plot of volume $(V)$ versus temperature $(T)$ in Kelvin. What does it represent?

Find the temperature in degree Celsius if volume and pressure of $2 \ mol$ ideal gas is $20 \ dm^3$ and $4.926 \ atm$ respectively. $(R = 0.0821 \ dm^3 \ atm \ K^{-1} \ mol^{-1})$