Question

Why does zinc decrease in mass after being placed in 1 molar of HCl?

Answer 1

The solid zinc lost mass because some of it reacted with the hydrochloric acid to form zinc chloride.

Explanation:

The reaction between zinc and hydrochloric acid produces zinc chloride and hydrogen gas. This is a single replacement reaction in which zinc replaces the hydrogen in hydrochloric acid. The balanced equation is:

`"Zn(s) + 2HCl(aq)"` `rarr` `"ZnCl"_2("aq") + "H"_2("g")`

The original zinc has lost mass because some of it reacted with the hydrochloric acid to form zinc chloride.