If 20 grams of zinc reacts with hydrochloric acid, how much zinc chloride is produced?

Answer 1

Okay. First make your balanced equation:
Zn+2HCL-->ZnCl2+2H

Now. there is excess HCL. That means Zn is your limiting reactant. So the find out zinc chloride in your stoichiometry you must use Zn.

The work:
g ZnCl2=(20 g Zn)(1 mole Zn/65.39g)(1 mole ZnCl2/1 mole Zn)(136.29g ZnCl2/1 mole)=40 grams.

The real answer is 41.68527298, but using the proper sig fig is 40 grams because 20 only has 1 sig fig (2).

Hope that helps!

Answer 2

The answer by Ashley is correct but the equation is not. Here is the correct equation.
Zn + 2HCL-->ZnCl2 + H2