Question

For the decomposition reaction $ 2A{g_2}C{O_3} \to 4Ag + 2C{O_2} + {O_2} $ , how many moles of reactant undergo decomposition reaction in order to produce $ 6.0 $ moles of $ Ag $ .

Answer 1

Hint: A reaction in which a compound breaks into two or more simpler molecules is known as decomposition reaction. For the question, the stoichiometric factors in the balanced chemical reaction will be used to compute the number of moles of silver carbonate used to produce given moles of silver.

Complete answer:
As per question, the given chemical reaction is as follows:
 $ 2A{g_2}C{O_3} \to 4Ag + 2C{O_2} + {O_2} $
In order to use stoichiometric factors, let’s first check whether the given chemical reaction is balanced or not. We know that in a balanced chemical reaction, the number of atoms of each element should exactly equal to the number of atoms of elements in the product. So, for the given reaction:

Element	Reactant	Product	Balanced
$ Ag $	4	4	Yes
$ C $	2	2	Yes
$ O $	6	6	Yes

Therefore, the given chemical reaction is balanced.
Now, in reference to this balanced chemical reaction, the stoichiometric factor relating silver carbonate in the reactant and silver in the product is as follows:
4 moles of $ Ag $ is produced by $ \Rightarrow $ 2 moles of $ A{g_2}C{O_3} $
So, 1 mole of $ Ag $ will be produced by $ \Rightarrow $ $ \dfrac{2}{4} $ moles of $ A{g_2}C{O_3} $
Therefore, 6 moles of $ Ag $ will be produced by $ \Rightarrow $ $ \dfrac{2}{4} \times 6 = 3 $ moles of $ A{g_2}C{O_3} $
Hence, we can conclude that the number of moles of reactant undergo decomposition reaction in order to produce $ 6.0 $ moles of $ Ag = 3 $ moles.

Note:
Remember that the stoichiometric coefficients in a balanced chemical reaction predict the ratio of each molecule in a chemical reaction and thus, can be used to compute moles of reactant, number of product molecules generated and relates masses of reactants and products as well.