$25 \ mL$ of $3.0 \ M \ HNO_3$ are mixed with $75 \ mL$ of $4.0 \ M \ HNO_3$. If the volumes are additive,the molarity of the final mixture would be ......... $M$.

$100 \ mL$ of $\frac{M}{10} \ Ca(NO_3)_2$ and $200 \ mL$ of $\frac{M}{10} \ KNO_3$ solutions are mixed. What is the normality of the resulting solution with respect to $NO_3^{-}$ ions (in $N$)?

What will be the molarity of $Cl^{-}$ ions in $M$ when $0.2 \, mol$ of $NaCl$ and $0.2 \, mol$ of $BaCl_2$ are dissolved in $500 \, mL$ of water?

If a $3.6 \, M$ solution of $H_2SO_4$ contains $29 \% \, H_2SO_4$ by mass,find the density of the $H_2SO_4$ solution. (Molar mass of $H_2SO_4 = 98 \, g \, mol^{-1}$)

$63 \ g$ of a compound (Mol. Wt. $= 126$) was dissolved in $500 \ g$ of distilled water. The density of the resultant solution is $1.126 \ g / mL$. The molarity of the solution is: (in $M$)

$A$ $6.50$ molal solution of $KOH$ $(aq.)$ has a density of $1.89 \ g \ cm^{-3}$. The molarity of the solution is .......... $mol \ dm^{-3}$.
(Round off to the Nearest Integer).
[Atomic masses: $K = 39.0 \ u, O = 16.0 \ u, H = 1.0 \ u$]