$A$ mixture of hydrogen and oxygen has volume $500 \, cm^3$,temperature $300 \, K$,pressure $400 \, kPa$,and mass $0.76 \, g$. The ratio of the mass of oxygen to the mass of hydrogen is:

Two ideal gases $A$ and $B$ having the same temperature $T$,same pressure $P$,and same volume $V$,are mixed together. If the temperature of the mixture is kept constant and the volume occupied by the mixture is reduced to $\frac{V}{2}$,then the pressure of the mixture will become:

$A$ mixture of $7 \, g$ of nitrogen and $11 \, g$ of carbon dioxide is kept in a container at a temperature of $T = 290 \, K$. If the pressure of the mixture is $1 \, atm$ $(1.01 \times 10^5 \, N/m^2)$,then the density of the mixture is approximately . . . . . . $kg/m^3$.

Two gases occupy two containers $A$ and $B$. The gas in $A$,of volume $0.10 \, m^3$,exerts a pressure of $1.40 \, MPa$,and the gas in $B$,of volume $0.15 \, m^3$,exerts a pressure of $0.7 \, MPa$. The two containers are connected by a tube of negligible volume,and the gases are allowed to intermingle. If the temperature remains constant,what will be the final pressure in the containers (in $MPa$)?

In a thermally isolated system,two boxes filled with an ideal gas are connected by a valve. When the valve is in the closed position,the states of box $1$ and $2$ respectively are $(1 \, atm, V, T)$ and $(0.5 \, atm, 4V, T)$. When the valve is opened,the final pressure of the system is approximately ............... $atm$.

Two different gases have pressure $P$ and temperature $T$. Their volume is $V$. If these two gases are mixed while keeping the volume and temperature the same,the pressure of the mixture will be...........