Conformational changes in ethane molecule leads the change in:

Options

A. torsional angle
B. bond angle
C. bond length
D. All of the above

Answer

To solve the question regarding conformational changes in the ethane molecule, we will follow these steps:

### Step 1: Understand the Structure of Ethane
Ethane (C2H6) consists of two carbon atoms connected by a single bond, with each carbon atom bonded to three hydrogen atoms. The molecular formula is C2H6.

**Hint:** Remember that ethane is a simple alkane with a straight-chain structure.

### Step 2: Identify Conformational Isomers
Conformational isomers are different arrangements of atoms that can be converted into one another by rotation around single bonds. In ethane, the two main conformations are:
- **Staggered conformation:** The hydrogen atoms on adjacent carbons are positioned as far apart as possible.
- **Eclipsed conformation:** The hydrogen atoms on adjacent carbons are aligned with each other.

**Hint:** Visualize the molecule in a Newman projection to see how the atoms are arranged in different conformations.

### Step 3: Analyze the Changes During Rotation
When we rotate the ethane molecule around the C-C bond, we transition between these staggered and eclipsed forms. During this rotation:
- The **torsional angle** changes. The torsional angle is defined as the angle between the hydrogen atoms on the front carbon and the hydrogen atoms on the back carbon.

**Hint:** Consider how the position of hydrogen atoms changes as you rotate the molecule.

### Step 4: Determine What Changes
As we rotate from staggered to eclipsed:
- In the staggered conformation, the torsional angle is approximately 60 degrees.
- In the eclipsed conformation, the torsional angle approaches 0 degrees.

Thus, the conformational changes lead to a change in the **torsional angle**.

**Hint:** Focus on the definition of torsional angle and how it varies between different conformations.

### Step 5: Conclusion
The conformational changes in the ethane molecule lead to a change in the **torsional angle** between the hydrogen atoms on adjacent carbon atoms.

**Final Answer:** Conformational changes in ethane molecule lead to the change in torsional angle.