$10 \, mL$ of $2 \, M \, NaOH$ solution is added to $200 \, mL$ of $0.5 \, M \, NaOH$ solution. What is the final concentration? $............ \, M$

$A$ solution is prepared by dissolving $24.5 \ g$ of sodium hydroxide in distilled water to give $1 \ L$ solution. The molarity of $NaOH$ in the solution is (Given that molar mass of $NaOH = 40.0 \ g \ mol^{-1}$) (in $M$)

The density of $3 \ M$ solution of $NaCl$ is $1.25 \ g \ mL^{-1}$. Calculate the molality of the solution.

$2 \ g$ of substance $A$ is added to $18 \ g$ of water to form a solution. Calculate the mass percentage of the solute. (in $\%$)

If $100 \ g$ of a $0.2 \ m$ aqueous solution is diluted by adding $200 \ g$ of water,what will be the molality of the resulting solution?

The molarity of the solution obtained by mixing $50 \ mL$ of concentrated $H_2SO_4$ $(36 \ N)$ with $50 \ mL$ of water is .......... $M$.