Zinc is added to a beaker containing hydrochloric acid, and the beaker gets warm. What type of reaction is this?

1 Answer
Apr 5, 2017

This is a redox reaction...........that also happens to be an exothermic reaction.

Explanation:

Zinc metal is oxidized to zinc ion:

Zn(s) rarr Zn^(2+) + 2e^- (i)

Hydrogen ion is REDUCED to dihydrogen gas:

2H_3O^(+) + 2e^(-) rarr H_2(g)uarr + H_2O(l) (ii)

For the overall reaction, we simply add (i) to (ii)

Zn(s) + 2HCl(aq) rarr ZnCl_2(aq) + H_2(g)uarr