$A$ 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 $\%$)

Three substances $A$,$B$ and $C$ react to form $E$ and $D$ as shown: $2A + 3B + C \rightarrow 4D + 2E$. If the molar masses of $A, B, C$ and $D$ are $40, 30, 20$ and $15 \ g/mol$ respectively,and $570 \ g$ of a stoichiometric mixture of $A, B$ and $C$ is reacted,the maximum mass of $E$ obtained will be ............ $g$.

What is the mass of potassium chloride produced when $12.25 \ g$ of potassium chlorate undergoes decomposition (in $g$)? (Atomic masses: $K=39, Cl=35.5, O=16$)

$A$ solution of $20.2 \, g$ of $1,2$-dibromopropane in $MeOH$ upon heating with excess $Zn$ produces $3.58 \, g$ of an unsaturated compound $X$. The yield $(\%)$ of $X$ is closest to [Atomic weight of $Br$ is $80$].

What will be the volume of oxygen gas produced if the reaction $2 KClO_{3(s)} \longrightarrow 2 KCl_{(s)} + 3 O_{2(g)}$,$\Delta H^{\circ} = -78 \ kJ$ is carried out at $S.T.P.$ (in $L$)?

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