$N_2$ is found in a $1 \ L$ flask under $100 \ kPa$ pressure and $O_2$ is found in another $3 \ L$ flask under $320 \ kPa$ pressure. If the two flasks are connected,the resultant pressure is $............... \ kPa$.

The graph of pressure $(P)$ versus density $(d)$ is shown for an ideal gas at two temperatures $T_1$ and $T_2$. Which of the following is correct?

$A$ box contains $0.90 \ g$ of liquid water in equilibrium with water vapour at $27^{\circ} C$. The equilibrium vapour pressure of water at $27^{\circ} C$ is $32.0 \ Torr$. When the volume of the box is increased,some of the liquid water evaporates to maintain the equilibrium pressure. If all the liquid water evaporates,then the volume of the box must be $.... \ litre$. [nearest integer]
(Given $R = 0.082 \ L \ atm \ K^{-1} \ mol^{-1}$)
(Ignore the volume of the liquid water and assume water vapours behave as an ideal gas.)

When an ideal gas undergoes free expansion,then:

At $400 \, K$ temperature,$200 \, mL$ of $N_2$ gas has a pressure of $1.5 \, bar$. Find the volume of $N_2$ gas at $STP$. (in $, mL$)

The compressibility factor for an ideal gas is