Ni(s) + 2HCl(aq) → NiCl2(aq) + H2(g)
In this reaction, nickel metal (Ni) undergoes an oxidation reaction, where it loses two electrons to form nickel(II) ions (Ni2+). The hydrogen ions (H+) in hydrochloric acid are reduced, gaining electrons to form hydrogen gas (H2).
The reactivity of nickel with hydrochloric acid depends on several factors, including the concentration of the acid, temperature, and the surface area of the nickel metal. Dilute hydrochloric acid at room temperature may react slowly with nickel, requiring some time to observe a significant reaction. However, concentrated hydrochloric acid and higher temperatures can accelerate the reaction, producing a more rapid evolution of hydrogen gas.
