Arrange the following in the increasing order of deviation from normal tetrahedral angle :

Options

A. `P_(4)ltPH_(3)ltH_(2)O`
B. `PH_(3)ltH_(2)OltP_(4)`
C. `P_(4)ltH_(2)OltPH_(3)`
D. `H_(2)OltPH_(3)ltP_(4)`

Explanation

To arrange the given molecules (P4, PH3, and H2O) in the increasing order of deviation from the normal tetrahedral angle (109.5°), we will analyze the bond angles in each molecule and how they deviate from this angle.

### Step 1: Identify the normal tetrahedral angle
The normal tetrahedral angle is approximately 109.5°.

### Step 2: Analyze the bond angles in each molecule
1. **P4 (White Phosphorus)**:
- P4 has a tetrahedral structure, but due to the larger size of phosphorus atoms and the nature of the bonding, the effective bond angle is much less than the tetrahedral angle.
- The bond angle in P4 is approximately 60°.
- Deviation from tetrahedral angle: 109.5° - 60° = 49.5°.

2. **PH3 (Phosphine)**:
- PH3 has a trigonal pyramidal shape due to the presence of one lone pair on phosphorus.
- The bond angle in PH3 is approximately 93.5°.
- Deviation from tetrahedral angle: 109.5° - 93.5° = 16°.

3. **H2O (Water)**:
- H2O has a bent shape due to two lone pairs on oxygen.
- The bond angle in H2O is approximately 104.5°.
- Deviation from tetrahedral angle: 109.5° - 104.5° = 5°.

### Step 3: Arrange the molecules in increasing order of deviation
Now we can arrange the molecules based on the calculated deviations:
- H2O: 5° deviation
- PH3: 16° deviation
- P4: 49.5° deviation

### Final Answer
The increasing order of deviation from the normal tetrahedral angle is:
**H2O < PH3 < P4**