Pick out the incorrect statement.

Options

A. The geometry around 'N' atom in trimethylamine is pyramidal
B. The geometry around N atom in trisilylamine is planar
C. The nitrogen atom in trimethylamine is `sp^(3)-` hybridized, whilst in trisilylamine it is `sp^(2)-` hybridized.
D. Trisilylamine has donor properties whilst trimethylamine has no donor properties

Answer

To solve the question "Pick out the incorrect statement," we will analyze each of the statements provided regarding trimethylamine and trisilylamine.

### Step-by-Step Solution:

1. **Understanding Trimethylamine:**
- Trimethylamine (N(CH3)3) has a nitrogen atom bonded to three methyl groups.
- The nitrogen atom has one lone pair of electrons and is surrounded by four regions of electron density (three C-H bonds and one lone pair).
- According to VSEPR theory, this results in a **trigonal pyramidal geometry** due to the presence of the lone pair.

**Hint:** Remember that the geometry is influenced by the number of bonding pairs and lone pairs around the central atom.

2. **Understanding Trisilylamine:**
- Trisilylamine (Si3NH) consists of a nitrogen atom bonded to three silicon atoms.
- The nitrogen atom in this case also has a lone pair of electrons.
- The geometry around the nitrogen atom can be analyzed similarly. However, silicon has a larger atomic radius and different hybridization characteristics compared to carbon.

**Hint:** Consider the hybridization of the nitrogen atom based on the number of bonding pairs and lone pairs.

3. **Hybridization of Nitrogen in Trisilylamine:**
- In trisilylamine, the nitrogen atom has three Si-N bonds and one lone pair.
- This leads to a total of four regions of electron density, which means the nitrogen is **sp3 hybridized**.
- The geometry around the nitrogen atom remains **trigonal pyramidal** due to the lone pair.

**Hint:** Check if the hybridization corresponds to the observed geometry.

4. **Comparing Donor Properties:**
- Trimethylamine is known to have donor properties due to its lone pair being available for donation.
- Trisilylamine, however, has its lone pair involved in partial bonding with silicon, which can reduce its ability to act as a donor.

**Hint:** Evaluate the electronic interactions and how they affect the donor properties of the compounds.

5. **Identifying the Incorrect Statement:**
- The statements regarding the hybridization and geometry of both trimethylamine and trisilylamine are correct.
- However, the statement claiming that "trimethylamine has no donor property" is misleading. Trimethylamine does have donor properties due to its lone pair.

### Conclusion:
The incorrect statement is that "trimethylamine has no donor property."