Two flasks of equal volume contain $O_2$ and $CH_3OH$ vapor respectively at $120\,^oC$ and $1.15\, atm$ pressure. Which of the following will be the same for both?

An empty $LPG$ cylinder weighs $14.8 \ kg$. When full,it weighs $29.0 \ kg$ and shows a pressure of $3.47 \ atm$. In the course of use at ambient temperature,the mass of the cylinder is reduced to $23.0 \ kg$. The final pressure inside of the cylinder is $....... \ atm$. (Nearest integer)
(Assume $LPG$ to be an ideal gas)

At $300 \ K$ and $760 \ torr$ pressure,the density of a mixture of $He$ and $O_2$ gases is $0.543 \ g \ L^{-1}$. The mass percent of oxygen is approximately $(R = 0.0821 \ L \ atm \ K^{-1} \ mol^{-1})$

The vapor pressure of water at $80\,^oC$ is $355.5\, mm\, of\, Hg$. $A$ $100\, mL$ vessel contains $O_2$ saturated with water vapor at $80\,^oC$,and the total pressure is $760\, mm\, of\, Hg$. If the contents are transferred to a $50\, mL$ vessel at the same temperature,what will be the partial pressure of $O_2$ in $mm\, Hg$?

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

The combination of plots which do not represent isothermal expansion of an ideal gas is