If you heat a mixture of Zn and HCl,and
heat them together until all liguid has evaporated because excess HCl will be given off. What substance is left in the dish after the liquid has evaporated.
Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g)
So H2 is a gas and goes up the fume hood, the evaporating water does the same as does any excess HCl. What's left?
Zn(s) + HCl(aqu)^ heat = ZnCl (zinc chloride)+ H(gaseous)
The equation by pem is not balanced and the ZnCl2 formula is incorrect. Also hyrogen is diatomic (H2).
When a mixture of zinc (Zn) and hydrochloric acid (HCl) is heated, a chemical reaction occurs. The reaction between these two substances produces hydrogen gas (H2) and zinc chloride (ZnCl2).
To understand what substance is left in the dish after the liquid has evaporated, we need to consider the reaction that takes place:
Zn + 2HCl -> ZnCl2 + H2
So, after the liquid has evaporated, the only substance left in the dish will be zinc chloride (ZnCl2). Zinc chloride appears as a white solid residue.
To confirm this, you could perform the experiment and observe the solid remains in the dish after the liquid has evaporated.