A Copper-Magnesium Cell in hydrochloric Acid

Materials Used

A Beaker of 1.0M Hydrochloric Acid: HCl

I used a 2.47V 0.3A light bulb

Wire strippers

Two wires soldered to the bulb

Two alligator clips to connect the wire to metal

A copper strip

A magnesium strip

Procedure

I first started by soldering the wire to the light bulb. I striped both ends of the wire and soldered one end to the light. I did the same with the other wire. I connected one alligator clip to one wire and the copper strip and the other to the other wire and the magnesium strip. I filled a beaker with 1M Hydrochloric acid. I then placed both metals into the one beaker of HCL and the light bulb lit up while the magnesium and copper strip bubbled Hydrogen gas. When I removed the metals the light turned off.

Explanation

The cool part about this reaction is that the reduction and oxidation are occurring in one solution. In this reaction the magnesium reacts with the acid in both oxidation and reduction. The oxidation converts MG(s) to MG2+ and 2e-. While the reduction is the bubbling of the H+ ion in the acid into H2(g). This makes the magnesium both the cathode and the anode, and because the reduction occurs on the surface of both metals the copper strip is an auxiliary cathode.

Oxidation: Mg (s) ----> Mg2+ + 2 e-

Reduction: 2 H+ (aq) + 2 e- ----> H2 (g)

Safety

Hydrochloric acid can be dangerous in high concentration, avoid any contact with skin and dilute with care in well vented areas. Even in low concentrations HCl can irritate skin or eyes wear safety goggles long sleeves and gloves. To dispose the acid you can simply rinse it down the drain with water assuming you are just using 1M HCl.

By Daniel Seilkop