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

$5 \ g$ of zinc is treated separately with an excess of
$(a)$ dilute hydrochloric acid and
$(b)$ aqueous sodium hydroxide.
The ratio of the volumes of $H_{2}$ evolved in these two reactions is:

Find the formula weight of the reactant if the formula weight of the product is $54 \ u$ and the percent atom economy is $75$. (in $u$)

The amount of calcium oxide produced on heating $150 \ kg$ of limestone ($75 \%$ pure) is $........... \ kg$ $(Nearest \ integer)$. Given: Molar mass (in $g \ mol^{-1}$) of $Ca = 40, O = 16, C = 12$.

The mass of a mixture containing $NaCl$ and $NaBr$ is $4.0 \ g$. If $Na$ is $30 \%$ of the total mixture,the composition of $NaCl$ in the mixture is (in $\%$)

Given the ratio of masses of nitrogen and oxygen in a particular gaseous mixture is $4: 1$. Calculate the ratio of the number of their molecules.