Kirti kept a metal spoon in a glass jar filled with pickle for a few days. She observed there were holes in the spoon. What could be the reason?
The reason for the holes in the spoon could be a chemical reaction known as corrosion. When a metal object like a spoon is in contact with a solution containing salt, such as pickle, and exposed to moisture, a process called electrolysis occurs. Here is the explanation of the process:
1. Electrolyte: The pickle in the jar contains salt, which acts as an electrolyte. An electrolyte is a substance that conducts electricity when dissolved in water.
2. Anode and Cathode: When the spoon is submerged in the pickle, it acts as an anode and a cathode. An anode is the electrode where oxidation occurs, and a cathode is the electrode where reduction occurs.
3. Oxidation: The metal spoon undergoes oxidation, which is the loss of electrons, at the anode. The oxygen present in the solution reacts with the metal surface of the spoon, causing the metal atoms to lose electrons. This process forms metal ions.
4. Reduction: At the same time, hydrogen ions (H+) from the electrolyte are reduced at the cathode, gaining electrons. This creates hydrogen gas (H2) bubbles on the surface of the spoon.
5. Overall Reaction: The oxidation of the metal and the reduction of the hydrogen ions happen simultaneously, leading to a chemical reaction known as corrosion. The metal ions dissolve in the electrolyte, causing the formation of holes or pits in the spoon.
To prevent this corrosion, it is important to keep metal objects away from corrosive substances like saltwater, acids, or other electrolytes.