State True or false
The standard potential of hydrogen half cell is zero at all conditions of temperature and pressure.

Explanation

To determine whether the statement "The standard potential of hydrogen half cell is zero at all conditions of temperature and pressure" is true or false, we can analyze the concept of the standard hydrogen electrode (SHE).

### Step-by-Step Solution:

1. **Understanding Standard Hydrogen Electrode (SHE)**:
- The standard hydrogen electrode is a reference electrode used in electrochemistry. It is defined to have a standard electrode potential of zero volts (0 V) under specific conditions.

2. **Conditions for Standard Potential**:
- The standard potential of the hydrogen half-cell is defined at a pressure of 1 atm (atmosphere) and a temperature of 298 K (25 °C).

3. **Evaluating the Statement**:
- The statement claims that the standard potential is zero at "all conditions of temperature and pressure." However, the standard potential of the hydrogen half-cell is only zero under the specific conditions of 1 atm and 298 K.

4. **Conclusion**:
- Since the standard potential does not remain zero under all conditions (it can change with variations in temperature and pressure), the statement is **false**.

### Final Answer:
The statement is **False**.