A voltaic electrochemical cell. The left half-cell contains the anode, a zinc electrode immersed in a 0.050 M solution of Zn2+ ions. The right half-cell contains the cathode, a copper electrode immersed in a 0.050 M solution of blue Cu2+ ions. The two half-cells are connected by a wire passing through a volt meter and salt bridge. The positive cell voltage of +0.86 V indicates that the reaction is favored.