Equal amounts of two gases of molecular weight $4$ and $40$ are mixed. The pressure of the mixture is $1.1 \, atm$. The partial pressure of the light gas in this mixture is ........... $atm$.

The radius of the $Na^{+}$ ion is $95 \ pm$ and that of $Cl^{-}$ ion is $181 \ pm$. Predict the coordination number of $Na^{+}$ in $NaCl$.

Solid $CO_2$ is known as dry ice,because

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?

The density of gas $A$ is twice that of $B$. The molecular mass of $A$ is half of $B$. The partial pressure ratio of $A$ and $B$ is

Based on the given figure,the number of correct statement/s is/are $........$.
$A.$ Surface tension is the outcome of equal attractive and repulsion forces acting on the liquid molecule in bulk.
$B.$ Surface tension is due to uneven forces acting on the molecules present on the surface.
$C.$ The molecule in the bulk can never come to the liquid surface.
$D.$ The molecules on the surface are responsible for vapour pressure if the system is a closed system.