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

The isobars of one mole of an ideal gas were obtained at three different pressures ($p_1$, $p_2$ and $p_3$). The slopes of these isobars are $m_1$, $m_2$ and $m_3$ respectively. If $p_1 < p_2 < p_3$, then the correct relation of the slopes is

$34.05 \, mL$ of phosphorus vapour weighs $0.0625 \, g$ at $546^{\circ} C$ and $0.1 \, bar$ pressure. What is the molar mass of phosphorus?

On a ship sailing in the Pacific Ocean where the temperature is $23.4^{\circ} C$,a balloon is filled with $2 \ L$ of air. What will be the volume of the balloon when the ship reaches the Indian Ocean,where the temperature is $26.1^{\circ} C$ (in $L$)?

The density of air is higher at sea level. Which of the following laws explains this practical observation?

The volume of a gas is $4 \ dm^3$ at $0^{\circ} C$. Calculate the new volume at constant pressure when the temperature is increased by $10^{\circ} C$. (in $dm^3$)