With respect to the conformers of ethane, which of the following statements is true ?

Options

A. Bond angle remains same but bond length changes.
B. Bond angle changes but bond length remains same.
C. Both bond angle and bond length change.
D. Both bond angles and bond length remains same.

Answer

To solve the question regarding the conformers of ethane and determine which statement is true, we will analyze the properties of ethane's conformers step by step.

### Step 1: Understanding Conformers
Conformers are different spatial arrangements of a molecule that can be interconverted by rotation around single bonds. In ethane (C2H6), the rotation occurs around the C-C bond.

**Hint:** Remember that conformers are related to the rotation around single bonds.

### Step 2: Identifying the Conformers of Ethane
Ethane has two primary conformers: the eclipsed and staggered conformations. In the eclipsed conformation, the hydrogen atoms on adjacent carbons are aligned with each other, while in the staggered conformation, they are positioned as far apart as possible.

**Hint:** Visualize the two main conformers of ethane to understand their spatial arrangement.

### Step 3: Analyzing Bond Angles and Bond Lengths
When considering the bond angles and bond lengths in ethane:
- The bond angles in ethane are approximately 109.5 degrees due to its tetrahedral geometry, and this angle remains constant regardless of the conformer.
- The bond lengths between carbon and hydrogen (C-H) and between carbon atoms (C-C) also remain constant during the rotation to form different conformers.

**Hint:** Focus on the fact that bond angles and lengths are intrinsic properties of the molecule that do not change with conformational rotation.

### Step 4: Conclusion
Based on the analysis, the true statement regarding the conformers of ethane is that both the bond angle and bond length remain constant regardless of the conformation.

**Final Statement:** The correct answer is that both bond angle and bond length remain the same in the conformers of ethane.