The decomposition of $CaCO_3$ produces $11.2 \, dm^3$ of $CO_2$ gas at $STP$. What mass of $KOH$ in grams is required to completely neutralize this gas?

The Molarity $(M)$ of an aqueous solution containing $5.85 \ g$ of $NaCl$ in $500 \ mL$ water is :
(Given : Molar Mass $Na: 23$ and $Cl: 35.5 \ g \ mol^{-1}$ )

What is the quantity of hydrogen gas liberated when $46 \ g$ sodium reacts with excess ethanol? (Given Atomic mass of $Na = 23$)

Match the following List-$I$ and List-$II$ at $STP$:

List-$I$	List-$II$
$A. 10 \ g \ CaCO_3 \xrightarrow{\Delta} \text{decomposition}$	$1. 0.224 \ L \ CO_2$
$B. 1.06 \ g \ Na_2CO_3 \xrightarrow{\text{Excess } HCl} \text{reaction}$	$2. 4.48 \ L \ CO_2$
$C. 2.4 \ g \ C \xrightarrow{\text{Excess } O_2} \text{combustion}$	$3. 0.448 \ L \ CO_2$
$D. 0.56 \ g \ CO \xrightarrow{\text{Excess } O_2} \text{combustion}$	$4. 2.24 \ L \ CO_2$
	$5. 22.4 \ L \ CO_2$

What is the concentration of sugar $(C_{12}H_{22}O_{11})$ in $mol \ L^{-1}$ if its $20 \ g$ are dissolved in enough water to make a final volume up to $2 \ L$?

$6.023 \times 10^{22}$ molecules are present in $10 \ g$ of a substance $'x'.$ The molarity of a solution containing $5 \ g$ of substance $'x'$ in $2 \ L$ solution is.......... $\times 10^{-3}$