Molarity of a given orthophosphoric acid solution is $3 \ M$. Its normality is (in $N$)

Volume of $0.1 \, M$ $H_2SO_4$ required to neutralize $30 \, mL$ of $0.2 \, N$ $NaOH$ is......$mL$

$19 \ g$ of a mixture containing $NaHCO_3$ and $Na_2CO_3$ on complete heating liberated $1.12 \ L$ of $CO_2$ at $STP$. The weight of the remaining solid was $15.9 \ g$. What is the weight (in $g$) of $Na_2CO_3$ in the mixture before heating?

How much $g$ of $NaOH$ is required to neutralize $1500 \, cm^3$ of $0.1 \, N$ $HCl$ (At. wt. of $Na = 23$)?

Concentrated nitric acid used in laboratory work is $68 \%$ nitric acid by mass in aqueous solution. What should be the molarity of such a sample of the acid if the density of the solution is $1.504 \, g \, mL^{-1}$ (in $, M$)?

If $1\frac{1}{2}$ moles of oxygen combine with $Al$ to form $Al_2O_3$,the weight of $Al$ used in the reaction is ............. $g$ $(Al=27)$.