A standard hydrogen electrode has zero electrode potential because :

Options

A. Hydrogen is easier to oxide
B. This electrode potential is assumed to be zero
C. Hydrogen atom has only one electron
D. Hydrogen is the lightest element

Explanation

To understand why a standard hydrogen electrode (SHE) has a zero electrode potential, we can break down the explanation into several steps:

### Step-by-Step Solution:

1. **Definition of Standard Hydrogen Electrode (SHE)**:
The standard hydrogen electrode is a reference electrode used in electrochemistry. It consists of a platinum electrode in contact with a solution of hydrogen ions (H⁺) at a concentration of 1 M, with hydrogen gas (H₂) at a pressure of 1 atm.

2. **Electrode Potential**:
The electrode potential is a measure of the tendency of a chemical species to acquire electrons and thereby be reduced. The potential is measured in volts (V).

3. **Setting the Reference Point**:
The SHE is assigned a potential of 0 volts. This is done for convenience and standardization in electrochemical measurements. It serves as a reference point against which the electrode potentials of all other half-cells can be measured.

4. **Why Zero Volts?**:
The zero value does not indicate that the SHE has no potential; rather, it is an arbitrary reference point. By convention, the potential of the SHE is set to zero so that the potentials of other electrodes can be expressed as positive or negative values relative to this standard.

5. **Implications of the Reference Point**:
When measuring the electrode potential of other half-cells, the values are compared to the SHE. If another half-cell has a positive potential, it means it is more favorable to be reduced than the SHE, while a negative potential indicates it is less favorable.

6. **Conclusion**:
Therefore, the standard hydrogen electrode has a zero electrode potential because it is defined as the reference point for measuring the electrode potentials of all other half-cells in electrochemistry.

### Final Answer:
The standard hydrogen electrode has a zero electrode potential because it is defined as the reference point for measuring the electrode potentials of all other half-cells.