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

The pressure exerted by a mixture of $3.2 \ g$ of methane $(CH_4)$ and $4.4 \ g$ of $CO_2$ contained in a $9 \ dm^3$ flask at $27^{\circ}C$ is: (in $atm$)

$20 \ mL$ of gas $A$ and $10 \ mL$ of gas $B$ diffuse through a porous membrane separately in $1 \ minute$. If the vapour density of $B$ is $x$,what is the vapour density of $A$?

If $4 \ g$ of oxygen gas diffuses through a fine hole,how many grams of hydrogen gas will diffuse under the same conditions?

At $STP$,$0.48 \, g$ of $O_2$ gas diffuses through a porous membrane in $1200 \, s$. What volume (in $mL$) of $CO_2$ gas will diffuse under the same conditions and in the same time?

Select the incorrect statement using the phase diagram of a substance.