The Standard Hydrogen Electrode (SHE) is a reference electrode used in electrochemistry to measure the voltage of other electrodes. Its voltage is defined as 0 volts, so it acts like a baseline.
How it is made:
- A platinum electrode is placed in an acidic solution.
- Hydrogen gas is bubbled over the platinum.
How it works:
- The electrode can either give or take electrons with hydrogen in the solution.
- By connecting another electrode to the SHE, we can measure its voltage compared to this standard.
Conditions:
- The hydrogen gas is at normal pressure.
- The acid solution is at a standard concentration.
- The temperature is room temperature.
Why it is important:
- It helps determine the strength of other electrodes.
- It is used in creating the electrochemical series.
- It serves as a reference in many electrochemical experiments.
In simple words: SHE is like a “zero point” in electrochemistry that helps us compare how strong other electrodes are.