$CaCO_3 + 2HCl \to CaCl_2 + CO_2 + H_2O$. In this chemical reaction,what will be the amount of $CaCl_2$ produced when $10 \ g$ of calcium carbonate and $200 \ mL$ of $0.75 \ M$ $HCl$ are used? $.............. \ g$

When copper is reacted with a certain concentration of nitric acid,nitric oxide and nitrogen dioxide are produced in equal volumes according to the following reaction:
$xCu + yHNO_3 \to xCu(NO_3)_2 + NO + NO_2 + 3H_2O$
What are the stoichiometric coefficients $x$ and $y$?

$250 \ mL$ of $0.5 \ M \ NaOH$ was added to $500 \ mL$ of $1 \ M \ HCl$. The number of unreacted $HCl$ molecules in the solution after complete reaction is $...... \times 10^{21}$. (Nearest integer) $(N_{A} = 6.022 \times 10^{23})$

The combustion of $1 \, \text{mol}$ of methanol in the presence of $O_2$ releases $723 \, \text{kJ mol}^{-1}$ of heat. If $1 \, \text{mol}$ of $O_2$ is used during this process,how much heat in $\text{kJ}$ will be produced?

The yield of $acetanilide$ in the reaction ($100\%$ conversion) of $2$ moles of $aniline$ with $1$ mole of $acetic$ $anhydride$ is (in $g$)

Calculate the amount of carbon dioxide produced when:
$(i)$ $1$ mole of carbon is burnt in air.
$(ii)$ $1$ mole of carbon is burnt in $16 \ g$ of dioxygen.
$(iii)$ $2$ moles of carbon are burnt in $16 \ g$ of dioxygen.