Two solutions of a substance (non-electrolyte) are mixed in the following manner: $480 \ mL$ of $1.5 \ M$ first solution $+ 520 \ mL$ of $1.2 \ M$ second solution. What is the molarity of the final mixture $.......... \ M$.

Sea water,which can be considered as a $6 \ M$ solution of $NaCl$,has a density of $2 \ g \ mL^{-1}$. The concentration of dissolved oxygen $(O_2)$ in sea water is $5.8 \ ppm$. Then the concentration of dissolved oxygen $(O_2)$ in sea water is $x \times 10^{-4} \ m$. $x = ............$ $(Nearest \ integer)$
Given: Molar mass of $NaCl$ is $58.5 \ g \ mol^{-1}$. Molar mass of $O_2$ is $32 \ g \ mol^{-1}$.

The molality of $648 \ g$ of pure water is .................. $m$.

The number of units,which are used to express the concentration of solutions from the following,is $.......$ Mass percent,Mole,Mole fraction,Molarity,ppm,Molality.

The molecular weight of urea is $60$. $A$ solution of urea containing $6 \ g$ of urea in one litre is ....... $molar$.

$A$ $2.0 \, M$ solution is obtained when $0.5 \, mole$ of solute is dissolved in: