What is meant by stoichiometry?

The mass of $CO_2$ that shall be obtained by heating $10 \ kg$ of $80\%$ pure limestone $(CaCO_3)$ is $:-$ (in $kg$)

Amount of oxygen required for combustion of $1 \, kg$ of a mixture of butane and isobutane is ............. $kg$.

What is obtained when one mole of calcium phosphide is reacted with excess water?

The concentrated sulphuric acid that is peddled commercially is $95\%\, H_2SO_4$ by weight. If the density of this commercial acid is $1.834\, g\, cm^{-3},$ the molarity of this solution is ........... $M$.

What is the quantity of water produced when $34.2 \ g$ of cane sugar is treated with concentrated $H_2SO_4$ under normal conditions of temperature and pressure (in $g$)?