# Zn + 2HCl → ZnCl2 + H2 How many moles of hydrogen are produced from the reaction of three moles of zinc with an excess of hydrochloric acid?

May 3, 2018

Would it not be THREE MOLES with respect to dihydrogen?

#### Explanation:

$Z n \left(a q\right) + 2 H C l \left(a q\right) \rightarrow Z n C {l}_{2} \left(a q\right) + {H}_{2} \left(g\right) \uparrow$
How do you know that hydrogen gas is bimolecular, i.e. diatomic? In fact all of the elemental gases, well all of the ones with any chemistry, are diatomic, i.e. H_2; O_2;F_2;N_2;Cl_2. You simply have to know this.