If you mix copper with hydrochloric acid, you will get copper(II) chloride (CuCl2) and hydrogen gas (H2). The chemical reaction that takes place is:

Cu + 2HCl → CuCl2 + H2

In this reaction, copper metal (Cu) reacts with hydrochloric acid (HCl) to form copper(II) chloride (CuCl2) and hydrogen gas (H2). The hydrogen gas is released as bubbles, and the copper(II) chloride remains in solution as a green-colored compound.