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 $, mL$)

At $27\,^oC$ temperature,$4\,mol$ $Cl_2$,$4\,mol$ $N_2$,and $2\,mol$ $O_2$ are filled in a $5\,L$ closed vessel. Find the total pressure of the gaseous mixture. $(R = 8.34 \times 10^{-2} \,bar \,L \,mol^{-1} \,K^{-1})$ (in $,bar$)

$A$ home owner uses $4.00 \times 10^{3} \ m^{3}$ of methane $(CH_{4})$ gas (assume $CH_{4}$ is an ideal gas) in a year to heat his home. Under the pressure of $1.0 \ atm$ and $300 \ K$,the mass of gas used is $X \times 10^{5} \ g$. The value of $X$ is $.......$ (Nearest integer).
(Given $R = 0.083 \ L \ atm \ K^{-1} \ mol^{-1}$)

Calculate the volume of $6.022 \times 10^{21}$ molecules of $CO_2$ at $300 \ K$ temperature and $2 \ bar$ pressure. $[R = 8.314 \times 10^{-2} \ bar \ L \ K^{-1} \ mol^{-1}]$ (in $mL$)

The pressure exerted by a non-reactive gaseous mixture of $6.4 \ g$ of methane and $8.8 \ g$ of carbon dioxide in a $10 \ L$ vessel at $27^{\circ} C$ is .............$kPa$.
(Round off to the Nearest Integer).
[Assume gases are ideal,$R = 8.314 \ J \ mol^{-1} K^{-1}$
Atomic masses $: C = 12.0 \ u, H = 1.0 \ u, O = 16.0 \ u]$

What is the numerical value of gas constant $R$ in terms of $L \ atm \ K^{-1} \ mol^{-1}$?