If $500 \ cm^3$ of hydrogen gas is at a pressure of $760 \ mm$ and a temperature of $300 \ K$,what is the number of moles?

The density of nitrogen monoxide $(NO)$ at $S.T.P.$ is ......... $g \ L^{-1}$.

In the gas equation $PV = nRT$,the universal gas constant $R$ depends on:

Pay load is defined as the difference between the mass of displaced air and the mass of the balloon. Calculate the pay load when a balloon of radius $10 \, m$,mass $100 \, kg$ is filled with helium at $1.66 \, bar$ at $27^{\circ} C$. (Density of air $= 1.2 \, kg \, m^{-3}$ and $R = 0.083 \, bar \, dm^{3} \, K^{-1} \, mol^{-1}$).

The $\log \, T$ vs $\log \, V$ curve is plotted for an ideal gas as shown. Which of the following is true for the gas?

At $25 \, ^\circ C$,the density of oxygen gas is $1.458 \, mg/L$ at $1 \, atm$ pressure. What will be the pressure of oxygen gas if the density is doubled?