How many grams of dihydrogen are required to react with dinitrogen to produce $34 \ g$ of ammonia (in $g$)?

When $3 \ g$ of $C_2H_6$ is completely burnt,find out the volume of $CO_2$ produced at $STP$ in $L$.

Calculate the mass of sodium acetate $(CH_{3}COONa)$ required to make $500 \,mL$ of $0.375 \,M$ aqueous solution. Molar mass of sodium acetate is $82.0245 \,g \,mol^{-1}$.

The weight of $1 \ L$ of a hydrocarbon is more than that of $1 \ L$ of $CO_2$ at the same temperature and pressure. What is the molecular formula of the hydrocarbon?

What is the volume (in litres) of oxygen at $STP$ required for complete combustion of $32 \,g$ of $CH_4$? (Molecular weight of $CH_4$ is $16$)

For the reaction $4FeCr_2O_4 + 8Na_2CO_3 + 7O_2 \rightarrow 8Na_2CrO_4 + 2Fe_2O_3 + 8CO_2$,what is the stoichiometric ratio of the reactants $(FeCr_2O_4 : Na_2CO_3 : O_2)$?