The colour of `[Ti(H_(2)O)_(6)]^(3+)` is due to

Options

A. absence of unpaired electrons in 'd' orbtials
B. charge transfer phenomenon
C. d-d electron transition
D. close packing crystal structure

Answer

To determine the color of the complex ion \([Ti(H_2O)_6]^{3+}\), we can follow these steps:

### Step 1: Identify the oxidation state of Titanium in the complex
Titanium in the complex \([Ti(H_2O)_6]^{3+}\) has an oxidation state of +3. This can be deduced from the overall charge of the complex, which is +3, and the neutral nature of water molecules.

**Hint:** The charge of the complex ion can help you determine the oxidation state of the central metal ion.

### Step 2: Determine the electronic configuration of Titanium
The atomic number of Titanium (Ti) is 22. The electronic configuration of neutral Titanium is \([Ar] 3d^2 4s^2\). When Titanium is in the +3 oxidation state, it loses three electrons, typically from the 4s and 3d orbitals. Therefore, the electronic configuration for \([Ti]^{3+}\) is \([Ar] 3d^1\).

**Hint:** Remember that electrons are removed first from the outermost shell (4s) before the inner shell (3d).

### Step 3: Analyze the presence of unpaired electrons
In the \([Ti]^{3+}\) ion, the electronic configuration is \(3d^1\), which means there is one unpaired electron in the 3d orbital.

**Hint:** Unpaired electrons are crucial for determining the color of transition metal complexes.

### Step 4: Understand the origin of color in transition metal complexes
The color of transition metal complexes arises from the d-d transitions of electrons. When light hits the complex, the unpaired electron can be excited from a lower energy d-orbital to a higher energy d-orbital. The specific wavelengths of light absorbed correspond to the energy difference between these orbitals, and the color observed is complementary to the color of light absorbed.

**Hint:** The presence of unpaired electrons allows for electronic transitions, which are responsible for the color.

### Step 5: Conclude the reason for the color of \([Ti(H_2O)_6]^{3+}\)
Since \([Ti(H_2O)_6]^{3+}\) has one unpaired electron, the color of the complex is due to d-d transitions of this unpaired electron. The specific color observed for this complex is typically purple.

**Hint:** The specific color can vary based on the ligand field and the nature of the ligands surrounding the metal ion.

### Final Answer
The color of \([Ti(H_2O)_6]^{3+}\) is due to d-d electron transitions facilitated by the presence of unpaired electrons in the d-orbitals.