Maximum potential energy of the molecule of ethane will be in the case when the dihederal angle will be

Options

A. `60^(@)`
B. `30^(@)`
C. `10^(@)`
D. `0^(@)`

Answer

To determine the dihedral angle at which the maximum potential energy of ethane occurs, we can analyze the conformations of ethane and how they relate to potential energy.

### Step-by-Step Solution:

1. **Understanding Dihedral Angle**:
The dihedral angle is the angle between two planes formed by four atoms in a molecule. In ethane (C2H6), we can visualize it by looking at the two carbon atoms and the hydrogen atoms attached to them.

2. **Conformational Analysis**:
Ethane can adopt different conformations, primarily staggered and eclipsed. The staggered conformation has the hydrogens on adjacent carbons positioned as far apart as possible, while the eclipsed conformation has them aligned.

3. **Potential Energy and Stability**:
The potential energy of a molecule is related to its stability. A conformation with higher potential energy is less stable. In ethane, the eclipsed conformation is the least stable due to increased steric hindrance and torsional strain.

4. **Identifying Eclipsed Conformation**:
In the eclipsed conformation, the dihedral angle between the hydrogen atoms on adjacent carbons is 0 degrees. This results in maximum repulsion between the electron clouds of the overlapping hydrogen atoms.

5. **Conclusion**:
Therefore, the maximum potential energy of ethane occurs when the dihedral angle is 0 degrees, as this corresponds to the eclipsed conformation with the least stability.

### Final Answer:
The maximum potential energy of the molecule of ethane will be in the case when the dihedral angle is **0 degrees**.

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