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 $(FeCr_2O_4 : Na_2CO_3 : O_2)$?

What is the volume occupied by $2 \ g$ of helium gas at $STP$ (in $dm^3$)? (molar mass of helium gas $= 4 \ g \ mol^{-1}$)

Aqueous $HCl$ reacts with $MnO_{2(s)}$ to form $MnCl_{2(aq)}$,$Cl_{2(g)}$ and $H_{2}O_{(l)}$. What is the weight (in $g$) of $Cl_{2}$ liberated when $8.7 \ g$ of $MnO_{2(s)}$ is reacted with excess aqueous $HCl$ solution? (Given Molar mass in $g \ mol^{-1}$: $Mn=55$,$Cl=35.5$,$O=16$,$H=1$)

What weight of $SO_2$ can be made by burning sulphur in $5.0 \ mol$ of oxygen?

$A$ gas weighing $2.4 \ g$ has a vapor density of $11.2$. What is its volume in $L$ at $STP$?

For the complete combustion of $1 \, mol$ of a compound with the molecular formula $C_xH_yO_z$,the number of moles of $O_2$ required is: