What is meant by stoichiometry?

How many grams of $NaOH$ will be required to prepare $250 \, mL$ of $0.1 \, M$ solution?

When a certain amount of ethylene is combusted,$6226 \, kJ$ of heat is released. If its enthalpy of combustion is $1411 \, kJ \, mol^{-1}$,the number of oxygen atoms consumed in the process at $STP$ will be ............... $N_A$.

$5 \ g$ of $NaOH$ was dissolved in deionized water to prepare a $450 \ mL$ stock solution. What volume (in $mL$) of this solution would be required to prepare $500 \ mL$ of $0.1 \ M$ solution?
Given: Molar Mass of $Na$,$O$,and $H$ is $23$,$16$,and $1 \ g \ mol^{-1}$ respectively.

Which of the following is required to neutralize $1 \ L$ of $1 \ N \ NaOH$?

What volume of $CO_{2(g)}$ at $STP$ is obtained by complete combustion of $6 \ g$ carbon (in $dm^3$)?