What is the approximate molality of $10 \% (w/w)$ aqueous glucose solution (in $m$)? (Molar mass of glucose $= 180 \ g \ mol^{-1}$)

If the density of a $1 \, m$ aqueous solution of $NaCl$ is $1.21 \, g/mL$,then the molarity of the solution is .......... (in $, M$)

Two solutions of a substance are mixed as follows: $480 \ mL$ of $1.5 \ M$ first solution + $520 \ mL$ of $1.2 \ M$ second solution. The molarity of the final solution will be ............. $M$.

If $5.85 \ g$ of $NaCl$ is dissolved in $90 \ g$ of water,then find out the mole fraction of $NaCl$.

$A$ solution is prepared by adding $1 \ mole$ of ethyl alcohol in $9 \ mole$ of water. The mass percent of solute in the solution is. . . . . . . (Integer Answer)
(Given : Molar mass in $g \ mol^{-1}$ Ethyl alcohol : $46$,
water : $18$)

Air is an example of a solution of