Bond angle in `PH_(3)` is

Options

A. Much less than `NH_(3)`
B. Much less than `PF_(3)`
C. Slightly more than `NH_(3)`
D. Much more than `PF_(3)`

Explanation

To determine the bond angle in PH₃, we will analyze the molecular structure and the influence of lone pairs on the bond angles. Here’s a step-by-step solution:

### Step 1: Identify the Molecular Structure of PH₃
- PH₃ (phosphine) consists of one phosphorus atom and three hydrogen atoms.
- The phosphorus atom has five valence electrons, and it forms three single bonds with hydrogen atoms.

**Hint:** Remember that the central atom's valence electrons determine the number of bonds it can form.

### Step 2: Determine the Hybridization of PH₃
- In PH₃, phosphorus uses its three p orbitals and one s orbital to form four hybrid orbitals (sp³ hybridization).
- However, one of these hybrid orbitals contains a lone pair of electrons.

**Hint:** Hybridization can be determined by counting the number of bond pairs and lone pairs around the central atom.

### Step 3: Analyze the Bond Angles
- The ideal bond angle for sp³ hybridized molecules is 109.5°.
- However, due to the presence of a lone pair, the bond angle is affected. Lone pairs exert greater repulsion than bond pairs.

**Hint:** Recall that lone pair-bond pair repulsion is stronger than bond pair-bond pair repulsion, which can lead to a decrease in bond angles.

### Step 4: Compare with NH₃ and PF₃
- In NH₃ (ammonia), the bond angle is approximately 107.8° due to the lone pair on nitrogen.
- In PF₃ (phosphorus trifluoride), the bond angle is approximately 98° due to the lone pair on phosphorus and the electronegativity of fluorine.

**Hint:** Compare the bond angles of similar molecules to understand the effect of lone pairs and electronegativity.

### Step 5: Conclusion
- The bond angle in PH₃ is significantly less than that in NH₃ (93° compared to 107.8°).
- Therefore, the correct answer is that the bond angle in PH₃ is much less than in NH₃.

**Final Answer:** The bond angle in PH₃ is much less than that in NH₃.