At what temperature does the volume of a gas become theoretically zero?

When $16 \, g$ of oxygen and $3 \, g$ of hydrogen are mixed at $760 \, mm$ pressure and $0 \, ^\circ C$,the total volume of the mixture will be approximately:

The following data is obtained for $1 \ mole$ of a gas. The gas behaves as an ideal gas in the pressure range (in $bar$):

$P \ (bar)$	$\frac{PV}{RT}$
$1$	$1$
$2$	$1$
$3$	$1$
$4$	$1.5$
$5$	$2.0$

What is the weight of $CH_4$ gas in a $9 \ L$ cylinder at $27 \ ^oC$ temperature and $1 \ atm$ pressure in $g$?

The pressure exerted by $6.0 \ g$ of methane gas in a $0.03 \ m^3$ vessel at $129^{\circ} C$ is $........ \ Pa$ (Atomic masses : $C = 12.01, H = 1.01$ and $R = 8.314 \ J K^{-1} mol^{-1}$)

$A$ gas occupies $100 \, cc$ volume at $0 \, ^oC$ temperature and $1 \, atm$ pressure. If the pressure is increased by $1.5$ times and the temperature is increased by one-third of its absolute temperature,what will be the final volume of the gas in $cc$?