$H_2$ evolved at $STP$ on complete reaction of $27 \ g$ of Aluminium with excess of aqueous $NaOH$ would be $............ \ L$

How many grams of $NaOH$ are required to neutralize $12.2 \ g$ of benzoic acid (in $g$)?

What amount of oxygen is used at $S.T.P$ to obtain $9 \ g$ water from a sufficient amount of hydrogen gas (in $dm^3$)?

$5 \, L$ of a gaseous mixture of ethane and propane are burnt to produce total $11 \, L$ of $CO_2$. Volume percent of $C_2H_6$ in the initial mixture is

The minimum amount of $O_2\,(g)$ consumed per gram of reactant is for the reaction: (Given atomic mass: $Fe = 56, O = 16, Mg = 24, P = 31, C = 12, H = 1$)

$A$ metal exists as an oxide with formula $M_{0.96} O$. Metal $M$ can exist as $M^{2+}$ and $M^{3+}$ in its oxide $M_{0.96} O$. The percentage of $M^{3+}$ in the oxide is nearly: (in $\%$)