During the evaporation of a liquid,$..........$

At $27^{\circ} C$, $500 \ mL$ of helium diffuses in $30 \ minutes$. What is the time (in hours) taken for $1000 \ mL$ of $SO_2$ to diffuse under the same experimental conditions?

$0.5 \ mol$ each of $H_2, SO_2$ and $CH_4$ are present in a container. If a hole is made in the container,what will be the order of partial pressures of the gases remaining in the container after $3 \ hours$?

Assertion : Wet air is heavier than dry air.
Reason : The density of dry air is more than density of water.

$A$ $4 : 1$ molar mixture of $He$ and $CH_4$ is kept in a vessel at $20 \ bar$ pressure. Due to a hole in the vessel,the gas mixture leaks out. What is the composition of the mixture effusing out initially?

At $290 \ K$,a vessel $(I)$ contains equal moles of three liquids $(A, B, C)$. The boiling points of $A, B$ and $C$ are $350 \ K, 373 \ K$ and $308 \ K$ respectively. Vessel $(I)$ is heated to $300 \ K$ and vapours were collected into vessel $(II)$. Identify the correct statements. (Assume vessel $(I)$ contains liquids and vapours and vessel $(II)$ contains only vapours)
$I.$ Vessel $- I$ is rich in liquid $B$
$II.$ Vessel $- II$ is rich in vapour of $C$
$III.$ The vapour pressures of $A, B, C$ in Vessel $(I)$ at $290 \ K$ follows the order $C > A > B$.