A pair of enantiomers is:

Options

A. a pair of non superimposable mirror image of each other
B. a pair of superimposable image of each other
C. always optically active if one is dextrorotatory then other will be laevorotatory by same magnitude
D. compounds having same boiling points

Answer

To determine a pair of enantiomers, we need to understand what enantiomers are and their characteristics. Here is a step-by-step solution to the question:

### Step 1: Understand Enantiomers
Enantiomers are a type of stereoisomer that are non-superimposable mirror images of each other. This means that if you were to place one enantiomer over its mirror image, they would not align perfectly.

**Hint:** Remember that enantiomers always come in pairs and are related to chirality.

### Step 2: Analyze the Statements
We are given four statements regarding enantiomers. We need to evaluate each statement to determine which ones are correct.

1. **Statement 1:** A pair of non-superimposable mirror images of each other.
- This statement is **correct** because it directly defines what enantiomers are.

2. **Statement 2:** A pair of superimposable mirror images of each other.
- This statement is **incorrect** because superimposable images do not represent enantiomers; they represent identical molecules.

3. **Statement 3:** Compounds having the same boiling point.
- This statement is **correct** because enantiomers have identical physical properties, including boiling points, except for their interaction with polarized light.

4. **Statement 4:** Always optically active; if one is dextro, then the other will be levorotatory by the same magnitude.
- This statement is **correct** because enantiomers rotate plane-polarized light in opposite directions (one clockwise and the other counterclockwise).

### Step 3: Conclusion
Based on the analysis:
- The correct statements regarding enantiomers are **1, 3, and 4**.

### Final Answer
A pair of enantiomers is defined by the first, third, and fourth statements being correct.

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