STATEMENT-1: Tetrahedral complexes with chiral structure exhibit optical isomerism .
and
STATEMENT-2: They lack plane of symmetry .

Options

A. Statement-1 is True , Statement-2 is True , Statement-2 is a correct explanation for Statement-1
B. Statement-1 is True , Statement-2 is True , Statement-2 is NOT a correct explanation for Statement-1
C. Statement-1 is True , Statement-2 is False
D. Statement-1 is False , Statement-2 is True

Answer

To analyze the statements provided in the question, we will break down the concepts of tetrahedral complexes, chirality, optical isomerism, and plane of symmetry step by step.

### Step 1: Understanding Tetrahedral Complexes
Tetrahedral complexes are coordination compounds where a central metal atom is surrounded by four ligands. The arrangement of these ligands forms a tetrahedron shape.

**Hint:** Remember that tetrahedral complexes have a coordination number of 4.

### Step 2: Definition of Chirality
A chiral structure is one that cannot be superimposed on its mirror image. For a tetrahedral complex to be chiral, all four ligands attached to the central metal must be different.

**Hint:** A chiral molecule must have all different substituents to ensure it has no symmetry.

### Step 3: Optical Isomerism
Optical isomerism occurs when a compound can exist in two forms that are mirror images of each other (enantiomers). For a tetrahedral complex to exhibit optical isomerism, it must be chiral.

**Hint:** Optical isomers are non-superimposable mirror images.

### Step 4: Plane of Symmetry
A plane of symmetry divides a molecule into two halves that are mirror images of each other. If a molecule has a plane of symmetry, it cannot be chiral and therefore cannot exhibit optical isomerism.

**Hint:** The absence of a plane of symmetry is crucial for chirality.

### Step 5: Analyzing Statement 1
Statement 1 claims that tetrahedral complexes with chiral structures exhibit optical isomerism. Since we established that chiral tetrahedral complexes with four different ligands do indeed show optical isomerism, this statement is true.

**Hint:** Check if the ligands are all different to confirm chirality.

### Step 6: Analyzing Statement 2
Statement 2 states that these complexes lack a plane of symmetry. Since we have established that a chiral tetrahedral complex cannot have a plane of symmetry, this statement is also true.

**Hint:** A lack of symmetry is essential for optical activity.

### Conclusion
Both statements are true, and Statement 2 correctly explains Statement 1. Therefore, the answer is:
**A: Both statements are true, and Statement 2 is the correct explanation for Statement 1.**