An ionic solid `"Lal"_(2)` shown electrical conduction due to presence of

Options

A. `La^(2+) and 2l^(-)`
B. `La^(3+), 2l^(-) and e^(-)`
C. `La^(2+), I_(2) and 2e^(-)`
D. `La^(3+), I_(2) and 3e^(-)`

Answer

To solve the question regarding the electrical conduction of the ionic solid \( \text{La}_2\text{I}_3 \), we need to analyze the components of the ionic solid and understand the conditions under which it can conduct electricity. Here’s a step-by-step solution:

### Step 1: Identify the Ionic Components
The ionic solid given is \( \text{La}_2\text{I}_3 \). This indicates that it consists of lanthanum ions (\( \text{La}^{3+} \)) and iodide ions (\( \text{I}^- \)).

### Step 2: Determine the Charge Balance
In \( \text{La}_2\text{I}_3 \):
- There are 2 lanthanum ions, each with a charge of \( +3 \), contributing a total charge of \( +6 \).
- There are 3 iodide ions, each with a charge of \( -1 \), contributing a total charge of \( -3 \).

The overall charge is balanced as follows:
\[ 2 \times (+3) + 3 \times (-1) = +6 - 3 = +3 \]
This shows that the formula is indeed balanced.

### Step 3: Understand Electrical Conductivity
Ionic solids typically do not conduct electricity in their solid state because the ions are fixed in place within the crystal lattice. However, they can conduct electricity when dissolved in water or melted, as the ions become free to move.

### Step 4: Presence of Water
The question states that \( \text{La}_2\text{I}_3 \) shows electrical conduction due to the presence of water. When \( \text{La}_2\text{I}_3 \) is dissolved in water, it dissociates into its constituent ions:
\[ \text{La}_2\text{I}_3 \rightarrow 2 \text{La}^{3+} + 3 \text{I}^- \]
This dissociation allows the ions to move freely in solution, enabling electrical conduction.

### Step 5: Conclusion
Thus, the electrical conduction of the ionic solid \( \text{La}_2\text{I}_3 \) is due to the presence of water, which allows the ions to dissociate and move freely.

### Final Answer
The ionic solid \( \text{La}_2\text{I}_3 \) shows electrical conduction due to the presence of water.

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