In chemistry, the amount of a substance that reacts according to a balanced chemical equation. In a balanced chemical equation, the molar
amounts of reactants and products are given by the numbers of each substance in the equation. The masses of each substance in the equation are in proportion to their molar masses. For example, in the reaction between carbon and oxygen, one mole of carbon (12 g) reacts with one mole of oxygen (32 g) to form one mole of carbon dioxide (44 g):
C + O2 ® CO2
Since the substances react in fixed proportion, the amount of carbon dioxide formed by any amount of carbon can be easily calculated. The amount of carbon dioxide formed will always be 44/12
times the amount of carbon. So 100 tonnes of carbon will form (100 × 44/12
) or 367 tonnes of carbon dioxide. This type of calculation is very important for industrial processes where knowledge of the amounts of materials being used and formed is required. Knowing the amounts of carbon dioxide formed by burning fossil fuels is important in estimating the effects of increasing carbon dioxide in global warming.
© RM 2014. Helicon Publishing is division of RM.