The weight of sodium carbonate required to prepare $500 \ mL$ of a semi-normal solution is .......... $g$.

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

The amount of metallic $Zn$ (atomic weight $= 65.4$) required to react with aqueous sodium hydroxide to produce $1 \ g$ of $H_2$ is $.... \ g$.

$20 \ mL$ of $CO_2$ gas are passed over excess of red hot coke. The volume of $CO$ evolved is ............. $mL$.
$CO_{2(g)} + C_{(s)} \to 2CO_{(g)}$

The weight of pure $NaOH$ required to prepare $250 \ cm^3$ of $0.1 \ N$ solution is ......... $g$. (in $g$)

Gastric juice contains about $3.0 \ g$ of $HCl$ per liter. If a person produces about $2.6 \ liters$ of gastric juice per day,find the number of antacid tablets required to neutralize all the $HCl$ produced. Consider each antacid tablet contains $400 \ mg$ of $Al(OH)_3$. [Given,atomic masses: $Al=27, O=16, H=1, Cl=35.5$]