Question

2Fe + 6HCl -> 2FeCl3 + 3H2 If 7.0 moles of HCl is added to enough iron that the HCl is completely used up, how many

Answer 1

Answer: 3.5 moles of hydrogen gas will be produced.

Explanation:

The balanced chemical equation is:

$2Fe+6HCl\rightarrow 2FeCl_3+3H_2$

As HCl gets completely used up, $HCl$ is the limiting reagent.

According to stoichiometry :

6 moles of $HCl$ produces =  3 moles of $H_2$

Thus 7.0 moles of  $HCl$ produces=$\frac{3}{6}\times 7.0=3.5moles$  of $H_2$

 Thus 3.5 moles of hydrogen gas will be produced.