How much oxygen is required to burn 24.2 coal?

Coal combustion reaction:
C + O2 = CO2.
1) According to the periodic table, we determine the molar mass of coal: 12.
2) Find the amount of coal substance. For this, the mass of coal given in the problem is divided by the molar mass found from the periodic table: 24.2 / 12 = 2.02 mol.
3) According to the reaction equation, there is one mole of coal for one mole of oxygen. Hence, the amount of oxygen is equal to the amount of coal and is equal to: 2.02 mol.
4) Find the mass of oxygen. To do this, we multiply the amount of oxygen by its molar mass: 2.02 * 16 = 32.32 g – the answer.