Question

How many moles $CO$ in this equation: $2CO + {O_2} \to 2C{O_2}?$

Answer 1

We need to understand and study the stoichiometry of the given balanced chemical equation. The mole concept is the key to solving problems. We must need to remember that the mole concept is a convenient concept for expressing the amount of a given substance. In chemistry, a mole is defined as the amount of a substance which contains Avogadro’s number of particles. We will now study the mole concept of the given reaction.

Complete step by step answer:
The given equation is $2CO + {O_2} \to 2C{O_2}$ .The number of moles of a substance can calculated by the following formula given below:
$n = \dfrac{N}{{{N_A}}}$
Where $n$ is the number of moles of the substance $N$ is the total number of entities of the particular element in the sample, and ${N_A}$ is the Avogadro’s constant whose value is $6.022 \times {10^{23}}$. Here ${N_A} = 1$ mole of ${O_2}$ since it is the limiting reagent and $N = 2$ which is the coefficient of $CO$.
Hence the number of moles of $CO$, $n = \dfrac{2}{1} = 2mols$ . Thus 2 moles of carbon monoxide, CO, combines with 1 mole of oxygen, $O_2$, to form 2 moles of carbon dioxide, $CO_2$.
Therefore, moles of $CO$ in this equation: $2CO + {O_2} \to 2C{O_2}$ is $2mols$

Note:
We need to note that in a balanced chemical equation, the stoichiometric coefficients express the number of moles of each species that takes part in the reaction. We have to remember that in addition, the limiting reactant which when consumed stops the entire reaction is taken as the ${N_A}$ in the mole concept. Note that we only write coefficients that are bigger than 1 in any balanced chemical equation.