Find out the molality of a solution prepared by dissolving $2.89 \ g$ of $NaCl$ in $0.159 \ L$ of water. The density of water is $1.00 \ g / mL$. (in $m$)

The molality of a solution,when $18 \ g$ of glucose is added to $18 \ g$ of $H_2O$,is: (in $m$)

Two solutions labeled as $3\,M\,HCl$ and $1\,M\,HCl$ are mixed in the ratio of $x : y$ by volume and the molarity of the resulting solution is $1.5\,M$. The molarity of the resulting solution if they are mixed in the ratio $y : x$ by volume is ....... $M$.

The quantity which changes with temperature is:

$300 \ g$ of $25\%$ solution and $400 \ g$ of $40\%$ solution are mixed by weight. Calculate the percentage of the solute by weight in the final mixture. (in $\%$)

If $4 \ g$ of $NaOH$ dissolves in $36 \ g$ of $H_2O$,calculate the mole fraction of each component in the solution. Also,determine the molarity of the solution (specific gravity of the solution is $1 \ g \ mL^{-1}$).