Answer:
4 moles of HCl will be required to produce 2 moles of H2.
Step-by-step explanation:
A balanced chemical equation gives the stoichiometric ration of moles of reactants required to produce a certain number of moles of products. The ratio of moles of reactants to moles of products is known as the mole ratio and is constant for a given chemical reaction.
In the given balanced equation of reaction shown below:
Zn + 2HCl → ZnCl2 + H2
The mole ratio of HCl and H2 is 2:1. This means that in this reaction between Zinc metal and hydrochoric acid to produc zinc chloride and hydrogen gas, every two moles of hydrochloric acid used in the reaction will result in the production of one mole of hydrogen gas.
Therefore for two moles of H2 to be obtained from the reaction, twice the number of moles of HCl is required.
Moles of HCl required = 2 × 2 moles = 4 moles of HCl.