$10 \ g$ of a piece of marble $(CaCO_3)$ was put into excess of dilute $HCl$ acid. When the reaction was complete,$1120 \ mL$ of $CO_2$ was obtained at $STP$. The percentage of pure $CaCO_3$ in the marble is $............ \%$.

$A$ sample of $NaClO_3$ is converted by heat to $NaCl$ with a loss of $0.16 \ g$ of oxygen. The residue is dissolved in water and precipitated as $AgCl$. The mass of $AgCl$ (in $g$) obtained will be (Given: Molar mass of $AgCl = 143.5 \ g \ mol^{-1}$)

$30.0 \ mL$ of the given $HCl$ solution requires $20.0 \ mL$ of $0.1 \ M$ sodium carbonate solution for complete neutralisation. What is the volume of this $HCl$ solution required to neutralise $30.0 \ mL$ of $0.2 \ M$ $NaOH$ solution (in $mL$)?

Consider the reaction
$4 HNO_{3(\ell)} + 3 KCl_{(s)} \rightarrow Cl_{2(g)} + NOCl_{(g)} + 2 H_{2}O_{(g)} + 3 KNO_{3(s)}$
The amount of $HNO_{3}$ required to produce $110.0 \ g$ of $KNO_{3}$ is $...... \ g$.
(Given: Atomic masses of $H, O, N$ and $K$ are $1, 16, 14$ and $39$ respectively.)

The composition of a sample of wustite is $Fe_{0.93} O_{1.00}$. The percentage of iron in the form of $Fe^{3+}$ ion is nearly:

How many grams of $HCl$ are required to prepare $1500 \, mL$ of $0.1 \, N \, HCl$ aqueous solution?