What is the mass of $KClO_{3(s)}$ required to liberate $22.4 \ dm^3$ of oxygen at $STP$ during thermal decomposition (in $g$)? (Molar Mass of $KClO_{3(s)} = 122.5 \ g/mol$)

The masses of carbon dioxide and water (in $g$) respectively formed during complete combustion of $10 \ g$ of glucose at $STP$ are

When a mixture of $4.44 \, g$ of $CaCl_2$ and $NaCl$ is treated with a sodium carbonate solution,$Ca^{2+}$ ions precipitate as $CaCO_3$. Upon heating,this precipitate yields $0.56 \, g$ of $CaO$. Calculate the percentage of $NaCl$ in the original mixture. (Atomic mass of $Ca = 40 \, g/mol$)

The volume of $0.1 \, M$ aqueous $KOH$ solution required for the complete neutralization of $20 \, mL$ of $0.1 \, M$ aqueous $H_3PO_3$ solution is .......... $mL$.

To neutralize completely $20 \ mL$ of $0.1 \ M$ aqueous solution of phosphorous acid $(H_3PO_3)$,the volume of $0.1 \ M$ aqueous $KOH$ solution required is .......... $mL$.

What is the weight of $50\%$ pure $HCl$ required to react completely with $100 \ g$ of $100\%$ pure limestone $(CaCO_3)$ (in $g$)?