How many moles of hydrogen gas can be produced if 0.78 moles of hydrochloric acid reacts with excess solid zinc according to the following chemical equation? 2 HCl + Zn = H2 + ZnCl2

The answer to your question is It will be formed 0.39 moles of H₂

Explanation:

Data

moles of H₂ = ?

moles of HCl = 0.78

moles of Zinc = excess

Balanced chemical reaction

              2 HCl  +  Zn  ⇒  1 H₂  +  ZnCl₂

Process

1.- Use proportions to solve this problem. Consider the coefficients of the balanced reaction.

               2 moles of HCl 1 mol of H₂

               0.78 moles of HCl  x

               x = (0.78 x 1) / 2

- Simplification

              x = 0.78 / 2

- Result

              x = 0.39 moles of H₂

i'm pretty sure its b i might be wrong though!