The equation Cu + 2HCl -> CuCl2 + H2

1. Detailed information about the equation Cu + 2HCl -> CuCl₂ + H₂:

   • The above equation represents a chemical reaction in which copper (Cu) reacts with hydrochloric acid (HCl) to form copper(II) chloride (CuCl₂) and hydrogen (H₂).

2. Reaction conditions:

   • Hydrochloric acid (HCl) needs to be highly concentrated.
   • The reaction occurs under normal temperature conditions.

3. Reaction process:

   • In the first step, copper reacts with hydrochloric acid to produce copper(II) chloride and hydrogen.
   • During this process, copper loses two electrons to become copper(II) ion (Cu₂+), while two hydroxide ions (H+) gain two electrons to become hydrogen gas (H₂).

4. Occurring phenomena:

   • Metallized copper will gradually dissolve when reacting with hydrochloric acid.
   • Bubbles of hydrogen gas are released.
   • The color of the solution gradually changes to blue, the characteristic color of copper(II) chloride.

Note: This reaction may not occur if the copper is not strong enough to displace hydrogen from hydrochloric acid.