$1.0 \ g$ of magnesium is burnt with $0.56 \ g \ O_2$ in a closed vessel. Which reactant is left in excess and how much? (At. $wt. \ Mg = 24, O = 16$)

Under similar conditions of pressure and temperature,$40 \, mL$ of slightly moist hydrogen chloride gas is mixed with $20 \, mL$ of ammonia gas,the final volume of gas at the same temperature and pressure will be ............. $mL$.

The amount of heat evolved when $500 \text{ cm}^{3}$ of $0.1 \text{ M } HCl$ is mixed with $200 \text{ cm}^{3}$ of $0.2 \text{ M } NaOH$ is (in $\text{ kJ}$)

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

Combustion of $50 \ mL$ methane is carried out with $150 \ mL$ of air containing $21 \%$ oxygen by volume. What will be the total volume of the gaseous mixture after the reaction? (Assume water is in the gaseous state and air contains $79 \%$ nitrogen by volume).
$CH_{4(g)} + 2O_{2(g)} \to CO_{2(g)} + 2H_2O_{(g)}$

Dinitrogen and dihydrogen react with each other to produce ammonia according to the following chemical equation: $N_{2(g)} + 3H_{2(g)} \to 2NH_{3(g)}$
$(i)$ Calculate the mass of ammonia produced if $2.00 \times 10^3 \ g$ of dinitrogen reacts with $1.00 \times 10^3 \ g$ of dihydrogen.
$(ii)$ Will any of the two reactants remain unreacted?
$(iii)$ If yes,which one and what would be its mass?