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

$7.5 \ g$ of a gas occupies $5.8 \ L$ of volume at $STP$. The gas is

$0.43 \ g$ of a metal of valence $2$ was dissolved in $50 \ mL$ of $0.5 \ M \ H_2SO_4$ solution. The unreacted acid required $14.2 \ mL$ of $1 \ M \ NaOH$ solution for neutralization. The atomic weight of the metal is: (in $u$)

$A$ mixture of $NO_2$ and $N_2O_4$ has a vapour density of $38.3$ at $270,^oC$. Calculate the number of moles of $NO_2$ in $100$ moles of the mixture.

How many grams of ethanol are required to obtain $280 \ mL$ of dihydrogen gas at $S.T.P.$ by the reaction of $C_2H_5OH$ with $Na$ metal? (Molar mass of ethanol = $46 \ g/mol$)

What will be the volume of $O_2$ gas at $STP$ for complete combustion of $7.8 \ g$ acetylene? ............ $L$