The number of molecules of $CO_2$ liberated by the complete combustion of $0.1 \ mol$ of graphite in air is

The heat of combustion of methane is given by the following equation. How many grams of methane are required to produce $445 \ kJ$ of heat (in $g$)?
$CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O \ (\Delta H = -891 \ kJ/mol)$

The number of millimoles and milliequivalents of $Ba(OH)_2$ in $0.2 \, L$ of $0.2 \, M \, Ba(OH)_2$ solution are respectively:

What is the weight of oxygen required for the complete combustion of $2.8 \, kg$ of ethylene? (in $kg$)

Write the reaction of aluminum with caustic soda and determine how many moles of $H_2$ gas will be produced at $STP$ from $54 \ g$ of $Al$. (in $mol$)

White phosphorus reacts with chlorine and the product hydrolyses in the presence of water. Calculate the mass of $HCl$ obtained by the hydrolysis of the product formed by the reaction of $62 \ g$ of white phosphorus with chlorine in the presence of water.