The molarity of a $NaOH$ solution prepared by dissolving $4 \ g$ of it in $250 \ mL$ of water is: (in $M$)

How much water is needed to dilute $10 \, mL$ of $10 \, N$ hydrochloric acid to make it exactly decinormal $(0.1 \, N)$? .......... $mL$

What volume of a solution of hydrochloric acid containing $73 \ g$ of acid per litre would be sufficient for the exact neutralization of sodium hydroxide obtained by allowing $0.46 \ g$ metallic sodium to act upon water? $(Cl = 35.5, Na = 23.0, O = 16, H = 1)$

The heat of combustion of ethene $(C_2H_4)$ is $1411 \, kJ$. If a certain amount of ethene is burned to produce $6226 \, kJ$ of heat,what is the volume of $O_2$ (at $S.T.P.$) consumed in the process?

What volume of ammonia is formed when $10 \ dm^3$ dinitrogen reacts with $30 \ dm^3$ dihydrogen at same temperature and pressure (in $dm^3$)?

$A$ mixture of $2.3 \ g$ formic acid and $4.5 \ g$ oxalic acid is treated with conc. $H_2SO_4$. The evolved gaseous mixture is passed through $KOH$ pellets. Weight of the remaining product at $STP$ is .......... $g$.