The value of the gas constant $R$ is closest to which of the following values?

Consider the figure provided. $1 \ mol$ of an ideal gas is kept in a cylinder,fitted with a piston,at the position $A$,at $18^{\circ} C$. If the piston is moved to position $B$,keeping the temperature unchanged,then '$x$' $L \ atm$ work is done in this reversible process. $x=$ . . . . . . $L \ atm$. (nearest integer) [Given : Absolute temperature $=^{\circ} C + 273.15$,$R=0.08206 \ L \ atm \ mol^{-1} \ K^{-1}$]

$4 \ g$ of an ideal gas $A$ (molar mass $= M_A$) present in a vessel of a volume $V \ L$ exerted a pressure of $5 \ atm$ at $300 \ K$. When $16 \ g$ of another ideal gas $B$ (molar mass $= M_B$) was introduced into this vessel at the same temperature,the pressure increased to $10 \ atm$. What is the correct relationship between $M_A$ and $M_B$?

If the volume of a gas is $V \ L$ at $P \ atm$ pressure and $27 \ ^oC$ temperature,what will be the volume of the gas at $-173 \ ^oC$ temperature and $P \ atm$ pressure if the amount of gas is doubled?

The pressure of an $LPG$ gas cylinder is $14.9 \ bar$,which is considered safe. If the pressure is $12 \ bar$ at $27 \ ^oC$,at what temperature will the cylinder blast (in $K$)?

Calculate the density of methane at $27\,^oC$ and $2.0\, atm$ pressure in $g\, L^{-1}$.